Lipophenol compounds and uses thereof

ABSTRACT

The present invention relates to a compound of formula (I) wherein: i is 0 or 1; j is 0 or 1; k is 0 or 1; R 1  and R 2  are in particular H, (C 1 -C 12 )alkyl, or a group of formula C(O)R; R is a, linear or branched, alkyl radical, comprising at least 19 carbon atoms; R 3  is H and k=0 when j=1; or, when j=0, R 3  is —C(O)R or -L-C(O)R; L, U and L″ are linkers; wherein, when j=0, at least one of the groups R 1 ; R 2  and R 3  comprises a radical R.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of USSN 15/303,797 filedOct. 13, 2016, now U.S. Pat. No. 10,011,620, which itself was a Rule 371filing from international application PCT/EP2015/058960 filed Apr. 24,2015, and that international application claimed priority to EuropeanPatent Application 14305607.5 filed Apr. 24, 2014.

The present invention concerns new lipophenol compounds, theirpreparation processes, as well as uses thereof, especially for thetreatment of neurodegenerative diseases.

Reactive carbonyl species, such as sugars, α-dicarbonyls or metabolitesderived from lipid oxidation, are involved in glycation andcross-linking reactions of nucleophiles (like proteins—Maillardreactions), and thus affect cellular viability leading to tissueinjuries. Aging-associated pathologies like age-related maculardegeneration (AMD) but also other neurodegenerative diseases such asAlzheimer and Parkinson, result from carbonyl stress, strongly connectedto oxidative stress.

Among those ones, retinal pathologies (AMD, namely) are a major publichealth issue in the world. Circumstantial evidences gathered over anumber of years have implicated retinal pigment epithelial (RPE)lipofuscin in the aetiology of atrophic AMD and genetic maculardegeneration like Stargardt disease. Major constituents of RPElipofuscin are the bisretinoid conjugate A2E, its photoisomers and itsoxidized metabolites. Pathologic A2E biosynthesis occurs when moleculesof all-trans-retinal (AtR, key constituent of the visual cycle), ratherthan undergoing a detoxifying reduction to retinol, accumulate and reactwith phosphatidylethanolamine (PE) through a dual carbonyl and oxidativestress (COS) (N. L. Mata, J. Weng, G. H. Travis, Invest. Ophthalmol.Vis. Sci. 2000, 41, S144-S144; and J. R. Sparrow, E. Gregory-Roberts, K.Yamamoto, A. Blonska, S. K. Ghosh, K. Ueda, J. Zhou, Prog. Retin. EyeRes. 2012, 31, 121-135). This reactive aldehyde itself also presents adirect toxicity, involved in retinal dystrophy.

Thus, anti-COS derivatives, able to reduce the toxicity of the maincarbonyl stressor, AtR, are proposed to reduce A2E formation and to slowdown the pace of lipofuscin deposit. Recent literature addressedquestion of the ability of (poly)phenols, already known to be potentantioxidant, to also trap reactive toxic electrophilic carbonylentities, showing them to be potent anti-carbonyl stressors (C. Y. Lo,W. T. Hsiao, X. Y. Chen, J. Food Sci. 2011, 76, H90-96; WO 2009/063440and WO 2009/063439). One of them is represented by the phloroglucinol,monomer of the abundant phlorotannins in brown algae, active ingredientof commercialized spasmolytic drugs, and which has already beenidentified to reduce oxidative stress damages in cultured cells.Phloroglucinol efficiency to scavenge acrolein,4-hydroxy-trans-2-nonenal (HNE) (two toxic α,β-unsaturated aldehydesderived from lipid peroxidation) and methylglyoxal) has been recentlyreported in physiological conditions. One disadvantage using suchcompound to treat retinal pathologies, is its low lipid solubility whichwould affect the bioavailability and reduce plasma concentrations.

There is thus a need for improving the efficiency of anti-COSderivatives, and especially for improving the bioavailability of suchanti-COS derivatives.

An aim of the present invention is to provide novel compounds having ananti-COS activity.

Another aim of the present invention is to provide compounds having ananti-COS activity with an improved lipid solubility.

Another aim of the present invention is to provide compounds having ananti-COS activity with an improved bioavailability.

The present invention relates to compounds having the following formula(I):

wherein:

-   -   i is 0 or 1;    -   j is 0 or 1;    -   k is 0 or 1;    -   R₁ is chosen from the group consisting of: H, (C₁-C₁₂)alkyl,        (C₃-C₆)cycloalkyl, and (C₆-C₁₀)aryl radicals; or R₁ may form a        heterocycloalkyl radical with the oxygen atom bearing it; or R₁        is a group of formula C(O)R, R being as defined below;    -   R₂ is chosen from the group consisting of: H, (C₁-C₁₂)alkyl,        (C₃-C₆)cycloalkyl, and (C₆-C₁₀)aryl radicals; or R₂ may form a        heterocycloalkyl radical with the oxygen atom bearing it; or R₂        is a group of formula C(O)R, R being as defined below;    -   R is a, linear or branched, alkyl radical, possibly interrupted        by one or several double bonds, comprising at least 19 carbon        atoms, and wherein one or several hydrogen atoms may be replaced        by deuterium atoms;    -   R₃ is H and k=0 when j=1; or, when j=0, R₃ is a group of formula        —C(O)R or —L—C(O)R, R being as defined above;    -   L is a linker having one of the following formulae (L1) or (L2):

wherein:

-   -   A₁ is an alkylene radical comprising from 3 to 6 carbon atoms;    -   A′₁ is an alkylene radical comprising from 1 to 6 carbon atoms,        optionally interrupted by one or several heteroatoms, such as        oxygen atoms;    -   X₁ is a radical —C(O)— or an alkylene radical comprising from 1        to 6 carbon atoms;    -   X₂ is a radical —C(O)— or an alkylene radical comprising from 1        to 6 carbon atoms;    -   X′₁ is chosen from the group consisting of: —O—, —N(R_(a))— or        an alkylene radical comprising from 1 to 6 carbon atoms,        optionally interrupted by one or several heteroatoms, such as        oxygen atoms, R_(a) being H or an alkyl group comprising from 1        to 6 carbon atoms;    -   L′ is a linker of formula -(A)_(p)-(X)_(q)—C(O)—, wherein:        -   p is 0 or 1;        -   q is 0 or 1;        -   A is an alkylene radical comprising from 1 to 6 carbon            atoms, optionally interrupted by one or several heteroatoms,            such as oxygen atoms,        -   X is —O—, —N(R_(b))— or an alkylene radical comprising from            1 to 6 carbon atoms, R_(b) being H or an alkyl group            comprising from 1 to 6 carbon atoms;    -   L″ is a linker chosen from the group consisting of:        (C₆-C₁₀)arylene, (C₁-C₁₂)alkylene,        (C₁-C₁₂)alkylene-(C₆-C₁₀)arylene,        (C₆-C₁₀)arylene-(C₁-C₁₂)alkylene, —CH═CH-(C₆-C₁₀)arylene and        (C₁-C₁₂)alkylene-CH═CH-(C₆-C₁₀)arylene radicals;        wherein, when j=0, at least one of the groups R₁, R₂ and R₃        comprises a radical R;        provided that the compound of formula (I) is other than the        following compound:

or their pharmaceutically acceptable salts, racemates, diastereomers orenantiomers.

In the context of the present invention:

-   -   the expression “C_(t)-C_(z)” means a carbon-based chain which        can have from t to z carbon atoms, for example C₁-C₃ means a        carbon-based chain which can have from 1 to 3 carbon atoms;    -   the term “an alkyl group” means: a linear or branched,        saturated, hydrocarbon-based aliphatic group comprising, unless        otherwise mentioned, from 1 to 12 carbon atoms. By way of        examples, mention may be made of methyl, ethyl, n-propyl,        isopropyl, butyl, isobutyl, tert-butyl or pentyl groups;    -   the term “alkylene” (or “alkylidene”) refers to a divalent        hydrocarbon radical, which may be linear or branched, comprising        from t to z carbon atoms, and in particular from 1 to 12 carbon        atoms, and preferably from 1 to 6 carbon atoms. When said        radical is linear, it may be represented by the formula        (CH₂)_(k) wherein k is an integer varying from t to z, and in        particular from 1 to 12, and preferably from 1 to 6;    -   the term “a cycloalkyl group” means: a cyclic carbon-based group        comprising, unless otherwise mentioned, from 3 to 6 carbon        atoms. By way of examples, mention may be made of cyclopropyl,        cyclobutyl, cyclopentyl, cyclohexyl, etc. groups;    -   the term “aryl group” means: a cyclic aromatic group comprising        between 6 and 10 carbon atoms. By way of examples of aryl        groups, mention may be made of phenyl or naphthyl groups;    -   the term “arylene” refers to an aromatic monocyclic, bicyclic or        tricyclic hydrocarbon ring system comprising from 6 to 14 carbon        atoms wherein any ring atom capable of substitution may be        substituted by a substituent. A preferred arylene group is        phenylene;    -   the term “a heterocycloalkyl” means: a 4- to 10-membered,        saturated or partially unsaturated, monocyclic or bicyclic group        comprising from one to three heteroatoms selected from O, S or        N; the heterocycloalkyl group may be attached to the rest of the        molecule via a carbon atom or via a heteroatom; the term        bicyclic heterocycloalkyl includes fused bicycles and spiro-type        rings.

By way of saturated heterocycloalkyl comprising from 5 to 6 atoms,mention may be made of oxetanyl, tetrahydrofuranyl, dioxolanyl,pyrrolidinyl, azepinyl, oxazepinyl, pyrazolidinyl, imidazolidinyl,tetrahydrothiophenyl, dithiolanyl, thiazolidinyl, tetrahydropyranyl,tetrahydropyridinyl, dioxanyl, morpholinyl, piperidinyl, piperazinyl,tetrahydrothiopyranyl, dithianyl, thiomorpholinyl or isoxazolidinyl.

When the heterocycloalkyl is substituted, the substitution(s) may be onone (or more) carbon atom(s) and/or on the heteroatom(s). When theheterocycloalkyl comprises several substituents, they may be borne byone and the same atom or different atoms.

The abovementioned “alkyl”, “cycloalkyl”, “aryl”, and “heterocycloalkyl”radicals can be substituted with one or more substituents. Among thesesubstituents, mention may be made of the following groups: amino,hydroxyl, thiol, oxo, halogen, alkyl, alkoxy, alkylthio, alkylamino,aryloxy, arylalkoxy, cyano, trifluoromethyl, carboxy or carboxyalkyl;

-   -   the term “a halogen atom” means: a fluorine, a chlorine, a        bromine or an iodine;    -   the term “an alkoxy group” means: an —O-alkyl radical where the        alkyl group is as previously defined. By way of examples,        mention may be made of —O-(C₁-C₄)alkyl groups, and in particular        the —O-methyl group, the —O-ethyl group as —O-C₃alkyl group, the        —O-propyl group, the -O-isopropyl group, and as —O-C₄alkyl        group, the —O-butyl, —O-isobutyl or —O-tert-butyl group;    -   the term “an alkylthio” means: an —S-alkyl group, the alkyl        group being as defined above;    -   the term “an alkylamino” means: an —NH-alkyl group, the alkyl        group being as defined above;    -   the term “an aryloxy” means: an —O-aryl group, the aryl group        being as defined above;    -   the term “an arylalkoxy” means: an aryl-alkoxy-group, the aryl        and alkoxy groups being as defined above;    -   the term “a carboxyalkyl” means: an HOOC-alkyl-group, the alkyl        group being as defined above. As examples of carboxyalkyl        groups, mention may in particular be made of carboxymethyl or        carboxyethyl;    -   the term “a carboxyl” means: a COOH group;    -   the term “an oxo” means: “═O”.

When an alkyl radical is substituted with an aryl group, the term“arylalkyl” or “aralkyl” radical is used. The “arylalkyl” or “aralkyl”radicals are aryl-alkyl-radicals, the aryl and alkyl groups being asdefined above. Among the arylalkyl radicals, mention may in particularbe made of the benzyl or phenethyl radicals.

The compounds herein described may have asymmetric centers. Compounds ofthe present invention containing an asymmetrically substituted atom maybe isolated in optically active or racemic forms. It is well-known inthe art how to prepare optically active forms, such as synthesis fromoptically active starting materials. All chiral, diastereomeric, racemicforms and all geometric isomeric forms of a compound are intended,unless the stereochemistry or the isomeric form is specificallyindicated.

The term “pharmaceutically acceptable salt” refers to salts which retainthe biological effectiveness and properties of the compounds of theinvention and which are not biologically or otherwise undesirable.Pharmaceutically acceptable acid addition salts may be prepared frominorganic and organic acids, while pharmaceutically acceptable baseaddition salts can be prepared from inorganic and organic bases. For areview of pharmaceutically acceptable salts see Berge, et al. ((1977) J.Pharm. Sd, vol. 66, 1). For example, the salts include those derivedfrom inorganic acids such as hydrochloric, hydrobromic, sulfuric,sulfamic, phosphoric, nitric, and the like, as well as salts preparedfrom organic acids such as acetic, propionic, succinic, glycolic,stearic, lactic, malic, tartaric, citric, ascorbic, pamoic, maleic,hydroxymaleic, phenylacetic, glutamic, benzoic, salicyclic, sulfanilic,fumaric, methanesulfonic, and toluenesulfonic acid and the like.

According to the present invention, in formula (I), R may be interruptedby one or several double bonds. In such embodiment, R may also be calledan alkenyl radical, which is a hydrocarbon group formed when a hydrogenatom is removed from an alkene group.

Within the present application, R corresponds to a residue of a fattyacid (said fatty acid having the formula RCOOH).

According to a particular embodiment, the possible double bond(s) of Ris(are) double bond(s) with the configuration Z.

The term “alkenyl” as employed herein includes partially unsaturated,nonaromatic, hydrocarbon groups.

According to an embodiment, in formula (I), R may comprise one orseveral deuterium atoms.

According to the present invention, in formula (I), A′₁ may be analkylene radical comprising from 1 to 6 carbon atoms, interrupted by oneor several heteroatoms, such as oxygen atoms. As an example, A′₁ maycomprise one or several group(s) of formula —(OCH₂CH₂)—.

The compounds of the invention are lipophenol compounds and thus phenolderivatives. They comprise a phenyl group which may carry one or severalphenol functions, each being possibly alkylated or acylated. Eachcompound according to the invention comprises at least one lipidic chainwhich corresponds to the R radical.

The compounds of the invention may also be called fatty acid-phenolicconjugates as they comprise a phenolic core on which is linked at leastone fatty acid chain.

The present invention concerns active ingredients which are able toscavenge at the same time free radical and carbonyl stressors (anti-COS)and are thus intended for the treatment of diseases involving bothcarbonyl and oxidative stress.

According to the present invention, the compounds of formula (I)comprise at least one radical R.

When j=1, the compounds comprise necessarily a radical R on the phenylgroup.

When j=0, at least one of the groups R₁, R₂ and R₃ comprises a radicalR.

According to an embodiment, R₃ is a group of formula C(O)R.

According to an embodiment, R₃ is a group of formula C(O)R, and R₁ andR₂ are H.

According to an embodiment, R₃ is a group of formula C(O)R, and at leastone of R₁ and R₂ is other than H.

According to an embodiment, R₃ is a group of formula C(O)R, R₁ is otherthan H and R₂ is H.

According to an embodiment, R₃ is a group of formula C(O)R, and R₁ andR₂ are alkyl groups as defined above.

According to an embodiment, in formula (I), when j=0, at most one of thegroups R₁, R₂ and R₃ is H.

According to an embodiment, in formula (I), when j=0, at least one ofthe groups R₁, R₂ and R₃ is an alkyl group as defined above. Preferably,said alkyl group is an isopropyl group.

The present invention also relates to compounds having the followingformula (I-1):

wherein L′, R and R₂ are as defined above in formula (I),

or their pharmaceutically acceptable salts, racemates, diastereomers orenantiomers.

The compounds of formula (I-1) correspond to compounds of formula (I)wherein i=1, j=1, k=0 and R₁ and R₃ are H.

According to an embodiment, in formula (I-1), R₂ is an alkyl group (Alk)as defined above in formula (I). Such compounds may be represented bythe following formula:

According to an embodiment, in formula (I-1), R₂ is H. Such compoundsmay be represented by the following formula:

The present invention also relates to compounds having the followingformula (I-1-1):

wherein L′, R and R₁ are as defined above in formula (I),

or their pharmaceutically acceptable salts, racemates, diastereomers orenantiomers.

The compounds of formula (I-1-1) correspond to compounds of formula (I)wherein i=1, j=1, k=0 and R₂ and R₃ are H.

According to an embodiment, in formula (I-1-1), R₁ is an alkyl group asdefined above, and in particular an isopropyl group.

According to an embodiment, in formula (I-1-1), L′ is a linker offormula -A-O—C(O)—, A being as defined above in formula (I). Preferably,L′ is —(CH₂)₃—O—C(O)—.

The present invention also relates to compounds having the followingformula (I-2):

wherein k, L″, R₁ and R₃ are as defined above in formula (I),

or their pharmaceutically acceptable salts, racemates, diastereomers orenantiomers. In these compounds, the lipidic part (corresponding to theR group) is comprised in the R₃ group. Depending on the nature of R₁, itmay also be comprised in this group (if R₁ is a group C(O)R).

The compounds of formula (I-2) correspond to compounds of formula (I)wherein j=0 and R₂ is H. Preferably, in formula (I-2), k=0. As above,compounds of formula (I-2) are other than the following compound

According to an embodiment, in formula (I-2), R₁ is H. Such compoundsmay be represented by the following formula:

According to an embodiment, in formula (I-2), R₁ is an alkyl group (Alk)as defined above in formula (I). Such compounds may be represented bythe following formula:

According to an embodiment, in formula (I-2), R₃ is a group of formulaC(O)R, R being as defined above. Such compounds may be represented bythe following formula:

In this formula, k is preferably 0.

According to an embodiment, in formula (I-2), R₁ is H and R₃ is a groupof formula C(O)R, R being as defined above. Such compounds may berepresented by the following formula:

In this formula, k is preferably 0.

According to an embodiment, in formula (I-2), R₁ is an alkyl group (Alk)as defined above in formula (I) and R₃ is a group of formula C(O)R, Rbeing as defined above. Such compounds may be represented by thefollowing formula:

In this formula, k is preferably 0.

According to an embodiment, in formula (I-2), R₁ is an alkyl group (Alk)as defined above in formula (I), k=0 and R₃ is a group of formula C(O)R,R being as defined above. Such compounds have the following formula(I-2-1):

Preferably, in formula (I-2-1), Alk is a methyl, isopropyl or n-propylgroup, and most preferably is an isopropyl group.

The present invention also relates to compounds having the followingformula (I-5):

wherein R is as defined above in formula (I), and R₁ is an alkyl groupcomprising from 1 to 12 carbon atoms,

or their pharmaceutically acceptable salts, racemates, diastereomers orenantiomers.

The compounds of formula (I-5) correspond to compounds of formula (I)wherein j=0, k=0, R₁ is an alkyl group as defined above and R₂ is H.

The present invention also relates to compounds having the followingformula (I-5-1):

wherein R is as defined above in formula (I),

or their pharmaceutically acceptable salts, racemates, diastereomers orenantiomers.

The compounds of formula (I-5-1) correspond to compounds of formula (I)wherein j=0, k=0, R₁ and R₃ are OCOR as defined above and R₂ is H.

The present invention also relates to compounds having the followingformula (I-6):

wherein k, L″, R₁, R₂ and R₃ are as defined above in formula (I),

or their pharmaceutically acceptable salts, racemates, diastereomers orenantiomers.

The compounds of formula (I-6) correspond to compounds of formula (I)wherein j=0.

According to an embodiment, in formula (I-6), k=0. Such compounds may berepresented by the following formula:

According to an embodiment, in formula (I-6) and (I-6-1), R₃ is C(O)R, Rbeing as defined above. Such compounds may be represented by thefollowing formula:

According to an embodiment, in formula (I-6) and (I-6-1), R₁ and R₂ areboth alkyl groups as defined above.

According to an embodiment, in formula (I-6) and (I-6-1), R₁ and R₂ areboth alkyl groups as defined above, and R₃ is C(O)R, R being as definedabove.

According to an embodiment, in formula (I-6) and (I-6-1), R₁, R₂ are R₃are C(O)R, R being as defined above.

The present invention also relates to compounds having the followingformula (I-3)

wherein A₁, X₁, X₂, R, and R₁ are as defined above in formula (I),

or their pharmaceutically acceptable salts, racemates, diastereomers orenantiomers.

The compounds of formula (I-3) correspond to compounds of formula (I)wherein j=0, k=0, R₂ is H, R₃ is -L-C(O)R, wherein R is as defined aboveand L is a linker of formula (L1).

According to an embodiment, in formula (I-3), R₁ is an alkyl group asdefined above, and preferably an isopropyl group.

According to an embodiment, in formula (I-3), X₁ and X₂ are —C(O)—.

According to an embodiment, in formula (I-3), A₁ is a linear alkyleneradical, preferably having 3 carbon atoms.

The present invention thus also relates to compounds having thefollowing formula (I-3-1):

wherein R and R₁ are as defined above in formula (I), R₁ beingpreferably an alkyl group, such as an isopropyl group.

The present invention also relates to compounds having the followingformula (I-4):

wherein R is as defined above in formula (I),

and R₁ is an alkyl group comprising from 1 to 12 carbon atoms,preferably an isopropyl group,

or their pharmaceutically acceptable salts, racemates, diastereomers orenantiomers.

Compounds of formula (I-4) correspond to compounds of formula (I)wherein j=0, k=1, R₁ is an alkyl group as defined above, R₂ is H, L″ is—CH═CH-phenylene-, and R₃ is —C(O)R, wherein R is as defined above.

The present invention also relates to compounds having the followingformula (I-4-1):

wherein

R is as defined above in formula (I),

R₂ is H or an alkyl group comprising from 1 to 12 carbon atoms,

R₃ is H or an alkyl group comprising from 1 to 12 carbon atoms,

or their pharmaceutically acceptable salts, racemates, diastereomers orenantiomers.

Compounds of formula (I-4-1) correspond to compounds of formula (I)wherein j=0, k=1, R₁ is —C(O)R, wherein R is as defined above, R₂ is Hor an alkyl group, L″ is —CH═CH-phenylene-, and R₃ is H or an alkylgroup.

According to an embodiment, in formula (I-4-1), R₂ is H.

According to an embodiment, in formula (I-4-1), R₃ is an alkyl group,preferably an isopropyl group.

According to an embodiment, in formula (I-4-1), R₂ is H, and R₃ is analkyl group, preferably an isopropyl group.

According to an embodiment, in formula (I-4-1), R₃ is H.

According to an embodiment, in formula (I-4-1), R₂ is an alkyl group,preferably an isopropyl group.

According to an embodiment, in formula (I-4-1), R₃ is H, and R₂ is analkyl group, preferably an isopropyl group.

The present invention also relates to compounds having the followingformula (I-4-2):

wherein R is as defined above in formula (I),

or their pharmaceutically acceptable salts, racemates, diastereomers orenantiomers.

Compounds of formula (I-4-2) correspond to compounds of formula (I)wherein j=0, k=1, R₁ is H, R₂ is —C(O)R, wherein R is as defined above,L″ is —CH═CH-phenylene-, and R₃ is H.

According to an embodiment, in formula (I), R₁ is a (C₁-C₁₂)alkyl group,preferably a (C₁-C₆)alkyl group. According to a preferred embodiment, R₁is an isopropyl group.

According to an embodiment, in the compounds of the invention, R is alinear or branched alkyl group, possibly interrupted by one or severaldouble bonds, comprising from 19 to 23 carbon atoms. According to apreferred embodiment, R is a linear group.

According to an embodiment, in the compounds of the invention, R is alinear or branched alkyl group, possibly interrupted by one or severaldouble bonds, comprising from 19 to 23 carbon atoms, and wherein one orseveral hydrogen atoms are replaced by deuterium atoms.

According to an embodiment, in the compounds of the invention, R is alinear or branched alkyl group, interrupted by at least one double bond,comprising from 19 to 21 carbon atoms.

According to an embodiment, in the compounds of the invention, R is alinear or branched alkyl group, interrupted by at least three doublebonds, preferably at least five double bonds, comprising from 19 to 21carbon atoms.

According to an embodiment, said double bonds have the configuration Z.

According to a preferred embodiment, R is a linear group.

According to an embodiment, in the compounds of the invention, R is thefollowing radical:

Such radical corresponds to the residue of docosahexaenoic acid (DHA).

According to an embodiment, in the compounds of the invention, R is theresidue of eicosapentaenoic acid (EPA).

According to another embodiment, in the compounds of the invention, R isone of the following radicals:

The preferred compounds according to the invention are as follows:

The present invention also relates to a process for preparing a compoundhaving the formula (I-2-1) as defined above,

said process comprising:

-   -   a step of reacting a fatty acid RCOOH with a compound having the        following formula (A-1):

GP being a hydroxyl protecting group, in particular TIPS(triisopropylsilyl),

for obtaining a compound of formula (A-2):

said step being in particular carried out in a solvent, such asdichloromethane, in the presence of DCC/DMAP, preferably at roomtemperature,

the duration of this step being preferably carried out for 5 hours, and

-   -   a step of deprotection of compound (A-2) for obtaining a        compound of formula (I-2-1).

The present invention also relates to a process for preparing compoundshaving the following formula (B-1):

wherein R₁ and R₂ are alkyl groups,

said process comprising a step of reacting a fatty acid RCOOH with acompound having the following formula (B-2):

said step being in particular carried out in a solvent, such asdichloromethane, in the presence of DCC/DMAP, preferably at roomtemperature,

the duration of this step being preferably carried out for 5 hours.

The present invention also relates to a process for preparing a compoundhaving the formula (C-1) as defined above,

said process comprising:

-   -   a step of reacting a fatty acid RCOOH with a compound having the        following formula (C-2):

GP being a hydroxyl protecting group, in particular TIPS(triisopropylsilyl),

for obtaining a compound of formula (C-3):

said step being in particular carried out in a solvent, such asdichloromethane, in the presence of DCC/DMAP, preferably at roomtemperature,

the duration of this step being preferably carried out for 5 hours, and

-   -   a step of deprotection of compound (C-3) for obtaining a        compound of formula (C-1).

The present invention also relates to a process for preparing a compoundhaving the formula (D-1) as defined above,

said process comprising:

-   -   a step of reacting a fatty acid RCOOH with a compound having the        following formula (D-2):

GP being a hydroxyl protecting group, in particular TIPS(triisopropylsilyl),

for obtaining a compound of formula (D-3):

said step being in particular carried out in a solvent, such asdichloromethane, in the presence of DCC/DMAP, preferably at roomtemperature,

the duration of this step being preferably carried out for 5 hours, and

-   -   a step of deprotection of compound (D-3) for obtaining a        compound of formula (D-1).

The present invention also relates to a process for preparing a compoundhaving the formula (E-1) as defined above,

said process comprising reacting a fatty acid RCOOH with a compoundhaving the above-mentioned formula (D-1),

said step being in particular carried out in a solvent, such asdichloromethane, in the presence of DCC/DMAP, preferably at roomtemperature, the duration of this step being preferably carried out for5 hours.

The compounds of formula (E-1) may also be prepared by reacting thefatty acid with phloroglucinol in the same operating conditions asdescribed above.

The present invention also relates to a process for preparing a compoundhaving the formula (F-1)

wherein X₁, A₁, X₂ and R are as defined above in formula (I-3),

said process comprising:

-   -   a step of reacting a compound having the following formula        (F-2):

with a compound having the following formula (F-3):

GP being a hydroxyl protecting group, in particular TIPS(triisopropylsilyl),

for obtaining a compound of formula (F-4):

-   -   and a step of deprotection of compound (F-4) for obtaining        compound of formula (F-1) as defined above.

In the above-mentioned processes, the steps of deprotection may becarried out by implementing well-known methods for the skilled person.

The present invention also relates to a pharmaceutical compositioncomprising a compound according to the invention, in association with apharmaceutically acceptable vehicle.

The present invention relates to a pharmaceutical composition comprisinga compound having one of the formulae as mentioned above, and inparticular having formula (I), (I-1), (I-1-1), (I-2), (I-2-1), (I-3),(I-3-1), (I-4), (I-4-1), (I-5), (I-5-1), (I-6) or (I-6-1), inassociation with a pharmaceutically acceptable vehicle.

The present invention also relates to a drug, comprising a compoundhaving formula (I) as defined above.

While it is possible for the compounds of the invention having formula(I) to be administered alone, it is preferred to present them aspharmaceutical compositions. The pharmaceutical compositions, both forveterinary and for human use, useful according to the present inventioncomprise at least one compound having formula (I) as above defined,together with one or more pharmaceutically acceptable carriers andpossibly other therapeutic ingredients.

In certain preferred embodiments, active ingredients necessary incombination therapy may be combined in a single pharmaceuticalcomposition for simultaneous administration.

As used herein, the term “pharmaceutically acceptable” and grammaticalvariations thereof, as they refer to compositions, carriers, diluentsand reagents, are used interchangeably and represent that the materialsare capable of administration to or upon a mammal without the productionof undesirable physiological effects such as nausea, dizziness, gastricupset and the like.

The preparation of a pharmacological composition that contains activeingredients dissolved or dispersed therein is well understood in the artand need not to be limited based on formulation. Typically suchcompositions are prepared as injectables either as liquid solutions orsuspensions; however, solid forms suitable for solution, or suspensions,in liquid prior to use can also be prepared. The preparation can also beemulsified. In particular, the pharmaceutical compositions may beformulated in solid dosage form, for example capsules, tablets, pills,powders, dragees or granules.

The choice of vehicle and the content of active substance in the vehicleare generally determined in accordance with the solubility and chemicalproperties of the active compound, the particular mode of administrationand the provisions to be observed in pharmaceutical practice. Forexample, excipients such as lactose, sodium citrate, calcium carbonate,dicalcium phosphate and disintegrating agents such as starch, alginicacids and certain complex silicates combined with lubricants such asmagnesium stearate, sodium lauryl sulphate and talc may be used forpreparing tablets. To prepare a capsule, it is advantageous to uselactose and high molecular weight polyethylene glycols. When aqueoussuspensions are used they can contain emulsifying agents or agents whichfacilitate suspension. Diluents such as sucrose, ethanol, polyethyleneglycol, propylene glycol, glycerol and chloroform or mixtures thereofmay also be used.

The pharmaceutical compositions can be administered in a suitableformulation to humans and animals by topical or systemic administration,including oral, rectal, nasal, buccal, ocular, sublingual, transdermal,topical, vaginal, parenteral (including subcutaneous, intra-arterial,intramuscular, intravenous, intradermal, intrathecal and epidural),intracisternal and intraperitoneal. It will be appreciated that thepreferred route may vary with for example the condition of therecipient.

The formulations can be prepared in unit dosage form by any of themethods well known in the art of pharmacy. Such methods include the stepof bringing into association the active ingredient with the carrierwhich constitutes one or more accessory ingredients. In general theformulations are prepared by uniformly and intimately bringing intoassociation the active ingredient with liquid carriers or finely dividedsolid carriers or both, and then, if necessary, shaping the product.

The present invention also relates to the compound of formula (I) asdefined above, for its use for the treatment of a pathology involvingboth carbonyl and oxidative stress.

According to the present invention, the term “pathology involving bothcarbonyl and oxidative stress” refers to a pathology (or disease) whichinvolves abnormal alkylation of important intra or extracellularbiological molecules: proteins, nucleic acids, glutathione, ethanolamineand many other ones like. This deleterious bond formation being dueeither to the reaction between nucleophilic functions of these moleculeswith reactive electrophiles (carbonyl species), thus said the carbonylstress (leading to glycation or Maillard reactions), or as well as tooxidant reactive oxygen species (ROS), thus said theoxidative stress.

In the context of the invention, the term “carbonyl stress” is theabnormal metabolism resulting from the enhanced electrophilic reactivityof carbonyl species, said the carbonyl stressors, such as osides(glucose, fructose, and like) and their derivatives (osones, glyoxal,methylglyoxal, glyoxylic acid and like), but also, such as the aldehydesformed upon lipid peroxidation (malondialdhyde, 4-hydroxynonenal =4-HNE,and like).

A compound according to the invention has an anti-carbonyl stressactivity because is able to efficiently reduce carbonyl stressortoxicity. It could then limit the formation of pathological glycatedproducts such as lipofuscins.

In the context of the invention, the term “oxidative stress” is theresult of an abnormal radical oxidation reaction taking place when a ROSis formed upon electron leakage during the respiration process. If thisoccurs in the bilayer membranes and in the presence of dioxygen, thealkyl radical oxidizes to the alkylperoxide radical which further reactsby abstracting one proton and one electron to another lipid of themembrane, which starts a chain oxidation reaction. This oxidative stressnot only causes new bond formation or the breaking down of the lipids,but also the harmful peroxidation processes, eventually leading toinflammation through the ecosanoid cascade and the release of thecytokines.

A compound according to the invention has an anti-oxidative stressactivity and is able to scavenge oxidative stressors (ROS), and thus toavoid the formation of the toxic oxidation products and the inflammatoryresponse, to quench any chain oxidation reaction, thus, in case ofStargardt disease, the production of the lipofuscin A2E.

According to the present invention, the pathology involving carbonyl andoxidative stress may be chosen from the group consisting of:inflammatory and infectious diseases, cardiovascular diseases, metabolicdiseases, cancer, retinal pathologies, and neurodegenerative diseases.

According to the present invention, the term “inflammatory diseases”refers to diseases characterized by a chronic inflammation. By“inflammation” is meant the phenomena by which the human body usuallydefends itself against aggression and which can manifest itself invarious symptoms such as swelling, heat or redness of the skin.

In the context of the invention, the term “infectious disease” refers toa disease caused by pathogenic microorganisms, such as bacteria,viruses, parasites or fungi. Infectious diseases include influenza (orflu).

In the context of the invention, a “cardiovascular disease” refers to adisease that involves the heart or blood vessels (arteries and veins).More particularly, a cardiovascular disease according to the inventiondenotes a disease, lesion or symptom associated with an atherogenesisprocess that affects the cardiovascular system. It includes especiallythe conditions in which an atheroma plaque develops as well as thecomplications due to the formation of an atheroma plaque (stenosis,ischemia) and/or due to its evolution toward an acute ischemic stroke(thrombosis, embolism, infarction, arterial rupture).

Cardiovascular diseases include coronary artery disease, coronary heartdisease, hypertension, atherosclerosis, in particular iliac or femoralatherosclerosis, angina pectoris, thrombosis, heart failure, stroke,vascular aneurysm, vascular calcification, myocardial infarction,cardiac dysrhythmia, vascular stenosis and infarction, and vasculardementia.

In the context of the invention, a “metabolic disease” denotes a diseasethat disrupts normal metabolism. Preferably, the metabolic diseaseaccording to the invention is a carbohydrate metabolism disorder.

As used herein a “carbohydrate metabolism disorder” denotes a diseasewherein the metabolism of carbohydrate, for example of glucose, isdisrupted. Carbohydrate metabolism disorders include diabetes, such astype II diabetes, high fasting glycemia, overweight and obesity.

According to the present invention, by the term “cancer” is meantmalignant solid tumors and/or disseminated hematological cancers and/ortheir metastasis. The terms “metastasis” or “metastatic diseases” referto secondary malignant tumors that are formed by cells from a primarymalignant tumor, which have moved to another localization. The term“hematological cancers” refers to types of cancer that affect blood,bone marrow, and lymph nodes such as myelomas, lymphomas or leukemias.

In the context of the invention, the term “retinal pathology” refers toa disease or disorder of the retina.

The retina pathologies include Stargardt disease which is a hereditaryretinal dystrophia linked to mutations of a gene encoding a lipidic(retinal) carrier of ATP-Binding Cassette subtype A4 (ABCA4) (Allikmetset al., 1997).

The term “neurodegenerative disease” is used throughout thespecification to identify a disease which is caused by damage to thecentral nervous system and can be identified by neuronal death. Theneuronal cell death observed in a neurodegenerative disease is oftenpreceded by neuronal dysfunction, sometimes by several years.Accordingly, the term “neurodegenerative disease” includes a disease ordisorder that is characterized by neuronal dysfunction and eventuallyneuronal cell death. Exemplary neurodegenerative diseases includeHIV-associated Dementia, multiple sclerosis, Alzheimer's Disease,Parkinson's Disease, amyotrophic lateral sclerosis, and Pick's Disease.

The present invention also relates to the compound of formula (I) asdefined above, for its use for the treatment of a pathology involvingboth carbonyl and oxidative stress, chosen from the group consisting of:atherosclerosis, type II diabetes, cancer, Alzheimer's disease,Parkinson's disease, Age-related Macular Degeneration (AMD), Stargardtdisease, and severe influenza viruses.

The present invention also relates to the use of a compound of formula(I) for the preparation of a medicament for the prevention and/ortreatment of a pathology involving both carbonyl and oxidative stress,said pathology being chosen from the group consisting of: inflammatoryand infectious diseases, cardiovascular diseases, metabolic diseases,cancer, retinal pathologies, and neurodegenerative diseases.

The present invention also relates to a method of prevention and/ortreatment of a disease selected from the group consisting of:inflammatory and infectious diseases, cardiovascular diseases, metabolicdiseases, cancer, retina pathologies, and neurodegenerative diseases,comprising the administration of a pharmaceutical acceptable amount of acompound of formula (I) defined above to a patient in need thereof.

In the context of the invention, the term “treating” or “treatment”, asused herein, means reversing, alleviating, inhibiting the progress of,or preventing the disorder or condition to which such term applies, orone or more symptoms of such disorder or condition.

FIGURES

FIG. 1 concerns dose-response results of compound 13b. It representsARPE-19 cell survival in the presence of AtR (25 μM).

FIG. 2 concerns the dose-dependent protection of compound 13b of neuralretina cell cultures exposed to atRal (**: P<0.005 and ***: P<0.0005).The white columns correspond to cells incubated with 50 μM atRal, thegrey columns correspond to cells incubated with 75 μM atRal and theblack columns correspond to cells incubated with 100 μM atRal.

FIG. 3 concerns the mitochondrial respiration in ARPE-19 cells (*:P<0.05, **: P<0.005, ***: P<0.0005 and ns: not significant) exposed toatRal, in presence or absence of 13b. The white columns correspond tothe inhibition of complex CI, the hatched columns correspond to theinhibition of complex CII, and the black columns correspond to theinhibition of both complexes.

FIG. 4 concerns the dose-dependent protection of several compounds ofthe invention of ARPE-19 cell cultures exposed to atRal, in condition toprove their scavenging properties (Co-treatment). It represents ARPE-19cell survival in the presence of AtR (25 μM) for several doses of eachcompound (5 μM, 10 μM, 40 μM, and 80 μM). PG-DHA corresponds to compound6, PG-di DHA corresponds to compound 7, PG-tri DHA corresponds tocompound 8, PG-OMe-DHA corresponds to compound 13a, PG-di OMe-DHAcorresponds to compound 15a, and PG-OiP-DHA corresponds to compound 13b.

FIG. 5 concerns the measure of the intrinsic activity of eachmitochondrial respiratory chain (MRC) complex (enzymology) and theirlevel of protein expression.

FIG. 6 concerns the characterization of atRAL-induced cell death. Thecolumns with hatchings represent the percentage of living ARPE-19 cells,the columns in black represent the percentage of early apoptotic cellsand the white columns represent the percentage of lateapoptotic/necrotic cells.

FIG. 7 relates to the comparison of the anti-oxidant efficacies ofphloroglucinol (white columns) and PG-OiP-DHA (hatched columns) in RPEprimary cells. It represents the cell viability (%) for these compoundsat different concentrations.

FIG. 8 relates to the comparison of the anti-carbonyl efficacies ofphloroglucinol (white columns) and PG-OiP-DHA (hatched columns) in RPEprimary cells. It represents the cell viability (%) for these compoundsat different concentrations.

FIG. 9 relates to the comparison of the anti-carbonyl efficacies ofphloroglucinol (white columns) and PG-OiP-DHA (hatched columns) incondition to prove their scavenging properties (Co-treatment), in RPEprimary cells. It represents the cell viability (%) for these compoundsat different concentrations.

FIG. 10 represents some compounds according to the invention asexplained in example 12, and FIG. 11 concerns the comparison of theanti- carbonyl efficacies in RPE cell lines of the compounds of FIG. 10.

FIG. 12 concerns the dose-dependent protection of several compounds ofthe invention of ARPE-19 cell cultures exposed to atRal, in condition toprove their intracellular action (pre-treatment). It represents ARPE-19cell survival in the presence of AtR (25 μM). For each compound, theleft column corresponds to the dose of 10 μM and the right columncorresponds to the dose of 40 μM.

FIG. 13 concerns the comparison of the anti-carbonyl efficacies of PGderivatives with (hatched columns) and without an alkyl group (whitecolumns) in ARPE-19 cell lines.

FIG. 14 concerns the efficacy of PG-OiP-DHA in the protection of themitochondrial activity, and

FIG. 15 concerns the analysis of MRC protein expression.

EXAMPLES Example 1: Synthesis of DHA-Phloroglucinol Conjugates

DHA used in the following synthesis was extracted from cod liver oilusing a process developed to concentrate PUFAs starting from fish oralgal oil. The process was carried out in one single step, in which fishliver oil was saponified in the presence of NaOH, free fatty acids wereextracted using liquid-liquid extraction and separated from theunsaponifiable material. Then, mono-unsaturated fatty acids wereeliminated using urea complexation, based on the difference in thespatial configuration of fatty acids according to their degree ofunsaturation. This crystallization process allowed to isolate a crudemixture of DHA and EPA (eicosapentaenoic acid C20:5 n-3), which afterpurification on reverse phase yielded 5% of DHA (starting from cod liveroil) with 85% of purity (impurities consisting of mono unsaturated fattyacids such as palmitoleic acid (C16:1 n-7) and oleic acid (C18:1 n-9)).

To obtain phloroglucinol-DHA conjugates with acceptable yield, a silylprotecting group such as triisopropylsilyl (TIPS) was selected becauseof its efficient deprotection in mild conditions in the presence ofester linkage.

The following scheme illustrates the implemented step for preparing theDHA-phloroglucinol conjugates of the invention.

The di-protected phloroglucinol 2 was prepared in an original way,starting from the total protection of phloroglucinol 1 using 3equivalents of TIPS-OTf in THF following by a slow mono-desilylationusing triethylamine trihydrofluoride (3 equiv. Et₃N-3HF) during 4 h. Theprocess allowed to prepare the intermediate 2 in 59% overall yield onthe two steps (only 30% could be obtained by a direct di-silylationprocess). Using the same amount of Et₃N-3HF and increasing the reactiontime (from 4 h to 8 h) the mono-protected derivative 8 was obtained in62%, while a controlled mono silylation (1eq. TIPS-OTf, at 0° C.) gaveno more than 38%. Then, the coupling reactions were performed usingclassical DCC/DMAP reagents and afforded DHA conjugates 4 and 5 in 74%and 66% yield respectively. The deprotection of TIPS groups wereperformed using Et₃N-3HF in THF at room temperature and afforded thedesired lipophenol 6 and 7 with 78% and 86% yield, without cleavage ofthe ester linkage or degradation of the polyunsaturated moiety.

Tri-DHA conjugate 8 was obtained in much better yield, starting fromdi-DHA-phloroglucinol 7 (73%), than from direct coupling ofphloroglucinol with 3 equivalents of DHA (only 8%). The weak couplingconversion could be explained because of steric constraint or a lessreactivity of phloroglucinol compared to its silylated derivatives.

The implemented steps as mentioned above are described hereafter indetail.

Extraction process of DHA from cod liver oil: Commercially available codliver oil (5 g, commercially available, Cooper, France) were dissolvedin a mixture of ethanol and water (35 mL, 95/5) in presence of NaOH(1.50 g) under argon atmosphere. The mixture was protected from thelight with a foil paper and heated at 82° C. during 2 h. The ethanolicfraction was evaporated and the residue was dissolved in hexane (30 mL)after heating. Then, water (25 mL) was added to the organic layer andunsaponifiable material was removed with repeated hexane extraction ofthe aqueous phase (4×30 mL of hexane). The aqueous phase containing thesoaps was acidified to pH 2 using HCl solution (50%). The fatty acidswere extracted with hexane (4×25 mL). The organic phase was concentratedunder reduced pressure to give 4.62 g of a crude fatty acids oil. Urea(13.86 g) and ethanol 95% (55 mL) were added to the crude residue. Themixture was heated at 60° C.-70° C., protected from the light, until themixture turned into a clear homogenous solution. Then, the mixture waskept at room temperature and then placed at 4° C. during 24h. Thecrystals formed were separated from the liquid by filtration. Thefiltrate obtained was diluted with water (35 mL) and acidified to pH 4-5with HCl solution (6N). Hexane (70 mL) was added and the solution wasstirred thoroughly for 1 h. The hexane layer containing the liberatedfatty acids was separated from the aqueous layer and washed with waterthree times (3×40 mL). The organic phase was dried with Na₂SO₄ andconcentrated under reduced pressure to give 820 mg of a crude mixture ofPUFAs, which was purified by preparative HPLC (column Atlantis Prep OBD™10 μm (19×250 mm), H₂O/MeOH 13/87 isocratic, detection 217 nm) to givepure DHA (266 mg, 5% w/w)). ¹H NMR (500 MHz; CDCl₃) δ_(H) 5.43-5.30 (m,12H, CH═CH), 2.85-2.80 (m, 10H, CH₂ bis-allylic), 2.42-2.40 (m, 4H,CH₂—C═O, CH₂ allylic), 2.07 (quint, J=7.5 Hz, 2H, CH₂ allylic), 0.98 (t,J=7.5 Hz, 3H, CH₃); MS (ESI) m/z 327 [M−H]⁻.

2-methyl-2-((1E,3E,5E)-4-methyl-6-(2,6,6-trimethylcyclohex-1-enyl)hexa-1,3,5-trienyl)-2H-chromene-5,7-diol; Chromene A: To a stirredsolution of trans-retinal (200 mg, 0.35 mmol) in ethanol (8 mL), wereadded phloroglucinol (48.28 mg, 0.35 mmol) and acetic acid (40 μL, 0.35mmol). The reaction was stirred at room temperature for 48 h, protectedfrom the light with foil paper. After concentration of is solvent underreduced pressure, the residue obtained was dissolved in AcOEt, (20 mL)and washed with water (10 mL). The organic layer was recovered, driedwith MgSO₄ and concentrated under reduced pressure. The residue obtainedwas purified by chromatography on silica gel (90/10 to 85/15pentane/AcOEt) to give Chromene A (112.4 mg, 41%) as a solidcontaminated by 13% of a by product. Chromene A was isolated afterpurification by preparative HPLC to furnish full characterization(gradient of hexane/AcOEt, t_(0′=100/0), t_(15′=90/10), t_(45′=80/20),t_(75′=70/30); 15 mL/min, column luna 5μ Silica 100A 250×21.20 mm,detection 254 nm).

R_(f) (CH₂Cl₂/MeOH) 0.4; ¹H NMR (500 MHz; CD₃OD) δ_(H) 6.63 (dd, J=11.5Hz, J=15.5 Hz, 1H, H₁₁), 6.63 (d, J=10.0 Hz, 1H, H₁₅), 6.14 (d, J=16.5Hz, 1H, H₇), 6.03 (d, J=16.5 Hz, 1H, H₈), 5.98 (d, J=11.0 Hz, 1H, H₁₀),5.85 and 5.81 (d, J=2.0 Hz, 1H, and d, J=2.5 Hz, 1H, H₁₈ and H₂₀), 5.75(d, J=15.0 Hz, 1H, H₁₂), 5.39 (d, J=10.0 Hz, 1H, H₁₄), 2.02-2.00 (m, 2H,H₄ (CH₂)), 1.86 (s, 3H, H₂₅ (CH₃)), 1.68 (s, 3H, H₂₄ (CH₃)), 1.67-1.60(m, 2H, H₃ (CH₂)), 1.49 (s, 3H, H₂₆ (CH₃)), 1.48-1.46 (m, 2H, H₂ (CH₂)),1.00 (s, 6H, H₂₂, H₂₃ (CH₃)); ¹³C NMR (125 MHz; CDCl₃ δ_(c) 159.7 (C₁₉),156.4 (C_(21/17)), 139.1 (C_(8,) 139.0 (C₆), 137.1 (C₁₂), 137.0 (C₉),130.4 (C₁₀), 129.9 (C₅), 127.6 (C₇), 126.3 (C₁₅), 123.1 (C₁₄), 119.1(C₁₁), 103.9 (C₁₆), 96.3 (C_(20/18)), 78.5 (C₁₃), 40.7 (C₂), 35.1 (C₁),33.9 (C₄), 29.3 (C_(22/23)), 27.6 (C₂₆), 21.8 (C₂₄), 20.3 (C₃), 12.6(C₂₅); HRMS (ESI-TOF) m/z: [M−H]⁻ calcd. for C₂₆H₃₁O₃ 391.2278; found391.2272; HPLC rt: 11.26 min, (Atlantis C18 5 μm (4.6×250 mm), H₂O 0.1%TFA/ACN, t_(0′=25/75), t_(25′=20/80), t_(28′=0/100), t_(33′=0/100),detection 298 nm).

General Procedure for coupling step between DHA and polyphenolicderivatives: DHA (1.1 equiv., 0.30 mmol) and each of the concernedphenolic derivatives (1 equiv., 0.27 mmol) were dissolved in dry CH₂Cl₂(6 mL). DCC (1.1 equiv., 0.30 mmol) and DMAP (0.1 equiv, 0.03 mmol) wereadded to the solution and the reaction was stirred at room temperaturefor 5 h under nitrogen. The mixture was left 2 h at 4° C. to inducedicyclohexylurea crystallization. The urea residue was then filteredoff, and the filtrate was washed with water and brine. The organic layerwas dried on MgSO₄ and concentrated under reduced pressure. Purificationof the crude material was performed by chromatography on silica gel toafford the desired lipophenol.

General Procedure for deprotection of TIPS protecting group onDHA-polyphenols derivatives: To a solution of the appropriate protectedDHA-polyphenol (1 equiv., 0.19 mmol) in anhydrous THF (13 mL), was addeddropwise triethylammonium trihydrofluoride (Et₃N-3HF, 3 equiv., 0.57mmol for mono-protected compounds or 6 equiv., 1.14 mmol fordi-protected derivatives). The reaction was stirred at room temperatureduring 4 h to 6 h, until completion of the reaction. AcOEt (40 mL) wasadded to the mixture and the organic layer was washed with water (15 mL)and brine (15 mL). The organic phase was dried (MgSO₄) and concentratedunder vacuum. The residue obtained was purified by chromatography onsilica gel to give the deprotected lipophenol.

1,3,5-tris(triisopropylsilyloxy)benzene 1: To a stirred solution ofphloroglucinol (1 g, 7.90 mmol) in dry THF (60 mL), triethylamine (3.68ml, 23 mmol) and triisopropylsilyl trifluoromethanesulfonate (TIPS-OTf)(7 mL, 23 mmol) were added dropwise. The reaction mixture was stirred atroom temperature during 2 h. AcOEt (60 mL) was added to the mixture andthe organic layer was washed with water (40 mL) and brine (40 mL). Theorganic phase was dried (MgSO₄) and concentrated under vacuum. Theresidue obtained was purified by chromatography on silica gel (99/1Hexane/AcOEt) to give the tri-protected phloroglucinol 1 (4.64 g, 98%)as a yellow oil.

R_(f) (pentane) 0.28; ¹H NMR (500 MHz; CDCl₃) δ_(H) 6.07 (s, 3H,CH_(aro)), 1.27-1.18 (m, 9H, CH—Si), 1.09 (d, J=7.3 Hz, 54H, (CH₃)₂C);¹³C NMR (125 MHz; CDCl₃) δ_(c) 157.4, 105.8, 18.1, 12.8; HRMS (ESI-TOF)m/z: [M+H]⁺ calcd. for C₃₃H₆₇O₃Si₃ 595.4392; found 595.4395.

3,5-bis(triisopropylsilyloxy)phenol 2: The tri-protected phloroglucinol1 (5.01 g, 8.43 mmol) was dissolved in dry THF (200 mL). Et₃N-3HF (2.90mL, 17.70 mmol) was added dropwise and the mixture was stirred at roomtemperature during 4 h. The reaction was followed by TLC and stopped inorder to avoid as much as possible the formation of di-deprotectedderivative. AcOEt (200 mL) was added to the mixture and the organiclayer was washed with water (200 mL) and brine (100 mL). The organicphase was dried (MgSO₄) and concentrated under vacuum. The residueobtained was purified by chromatography on silica gel (95/5pentane/AcOEt) to give the di-protected phloroglucinol 2 (2.25 g, 60%)as a yellow oil. The mono-protected derivative 3 was isolated in 18% asa white solide (0.45 g).

R_(f) (pentane/AcOEt 80/20) 0.8; ¹H NMR (500 MHz; CDCl₃) δ_(H) 6.03 (t,J=2.0 Hz, 1H, CH_(aro)), 6.01 (d, J=2.0 Hz, 2H, CH_(aro)), 1.27-1.19 (m,6H, CH—Si), 1.09 (d, J=7.3 Hz, 36H, (CH₃)₂C); ¹³C NMR (125 MHz; CDCl₃)δ_(c) 157.8, 157.0, 105.1, 101.1, 18.1, 12.8; HRMS (ESI-TOF) m/z: [M−H]⁻calcd. for C₂₄H₄₅O₃Si₂ 437.2907; found 437.2911.

(4,7,10,13,16,19 Z)-3,5-bis(triisopropylsilyloxy)phenyl-docosa-4,7,10,13,16,19-hexaenoate 4: Coupling of the di-TIPS-phloroglucinol 2(130 mg, 0.29 mmol) and DHA (104 mg, 0.32 mmol) was performed accordingto the general procedure and afforded 4 (164 mg, 74%) as an uncoloredoil after purification on silica gel chromatography (hexane/AcOEt99.7/0.3 to 99/1).

R_(f) (hexane/AcOEt 99/1) 0.23; ¹H NMR (500 MHz; CDCl₃) δ_(H) 6.29-6.27(m, 1H, CH_(aro)), 6.25-6.24 (m, 2H, CH_(aro)), 5.45-5.30 (m, 12H,CH═CH), 2.87-2.81 (m, 10H, CH₂ bis-allylic), 2.57 (t, J=7.3 Hz, 2H,CH₂—C═O), 2.52-2.48 (m, 2H, CH₂ allylic), 2.07 (quint, J=7.5 Hz, 2H, CH₂allylic), 1.26-1.18 (m, 6H, CH—Si), 1.08 (d, J=7.5 Hz, 36H, (CH₃)₂C),0.97 (t, J=7.5 Hz, 3H, CH₃); ¹³C NMR (125 MHz; CDCl₃) δ_(c) 171.1,157.1, 151.8, 132.0, 129.6, 128.6, 128.3, 128.3, 128.2, 128.1, 128.1,128.0, 127.9, 127.0, 109.2, 106.9, 34.4, 25.6, 25.5, 22.7, 20.6, 17.8,14.2, 12.7; HRMS (ESI-TOF) m/z: [M+H]⁺ calcd. for C₄₆H₇₇O₄Si₂ 749.5354;found 749.5363.

(4,7,10,13,16,19Z)-3,5-dihydroxyphenyl-docosa-4,7,10,13,16,19-hexaenoate 6: Deprotectionof the protected DHA-phloroglucinol 4 (50 mg, 0.07 mmol) was performedusing the general procedure and afforded 6 (23 mg, 78%) as an uncoloredoil after purification on silica gel chromatography (hexane/AcOEt 9/1 to75/25).

R_(f) (hexane/AcOEt 70/30) 0.36; ¹H NMR (500 MHz; CDCl₃) δ_(H) 6.06 (s,3H, CH_(aro)), 5.48⁻5.28 (m, 12H, CH═CH), 2.87-2.79 (m, 10H, CH₂bis-allylic), 2.63 (t, J=7.0 Hz, 2H, CH₂—C═O), 2.53-2.48 (m, 2H, CH₂allylic), 2.06 (quint, J=7.5 Hz, 2H, CH₂ allylic), 0.96 (t, J=7.5 Hz,3H, CH₃); ¹³C NMR (125 MHz; CDCl₃) δ_(c) 172.7, 157.3, 151.8, 132.0,129.9, 128.6, 128.4, 128.3, 128.3, 128.1, 128.0, 127.8, 127.8, 127.2,127.0, 101.9, 101.1, 34.3, 25.6, 25.6, 25.6, 25.5, 22.7, 20.5, 14.2;HRMS (ESI-TOF) m/z: [M−H]⁻ calcd. for C₂₈H₃₅O₄ 435.2535; found 435.2538.

5-(triisopropylsilyloxy)benzene-1,3-diol 3: The tri-protectedphloroglucinol 1 (200 mg, 0.33 mmol) was dissolved in dry THF (12 mL).Et₃N-3HF (164 μl mL, 1 mmol) was added dropwise and the reaction wasfollowed by TLC and stopped in order to reduce as much as possible theformation of the mono-deprotected derivative. After 6 h of stirring atroom temperature, 1 additional equivalent of Et₃N-3HF is added to themixture. The reaction was stopped after 8 h. AcOEt (15 mL) was added tothe mixture and the organic layer was washed with water (10 mL) andbrine (10 mL). The organic phase was dried (MgSO₄) and concentratedunder vacuum. The residue obtained was purified by chromatography onsilica gel (pentane/AcOEt 95/5) to give the mono-protectedphloroglucinol 3 (59 mg, 62%) as a white solide. The di-protectedderivative 2 was isolated in 13% as a yellow oil (20 mg).

R_(f) (hexane/AcOEt 70/30) 0.34; ¹H NMR (500 MHz; CDCl₃) δ_(H) 5.99 (d,J=2.0 Hz, 2H, CH_(aro)), 6.01 (t, J=2.0 Hz, 1H, CH_(aro)), 1.27-1.18 (m,3H, CH—Si), 1.08 (d, J=7.5 Hz, 18H, (CH₃)₂C); ¹³C NMR (125 MHz; CDCl₃)δ_(c) 158.2, 157.3, 100.5, 96.5, 18.0, 12.8; HRMS (ESI-TOF) m/z: [M−H]⁻calcd. for C₁₅H₂₅O₃Si 281.1573; found 281.1570.

(4,4′,7,7′,10,10′,13,13′,16,16′,19,19′Z)-5-(triisopropylsilyloxy)-1,3-phenylene-didocosa-4,7,10,13,16,19-hexaenoate 5: Coupling of themono-TIPS-phloroglucinol 3 (86 mg, 0.30 mmol) and DHA (200 mg, 0.60mmol) was performed with the general procedure and afforded 5 (183 mg,66%) as an uncolored oil after purification on silica gel chromatography(pentane/AcOEt 98/2).

R_(f) (pentane/AcOEt 98/2) 0.34; ¹H NMR (500 MHz; CDCl₃) δ_(H) 6.51 (s,3H, CH_(aro)), 5.47-5.28 (m, 24H, CH═CH), 2.87-2.80 (m, 20H, CH₂bis-allylic), 2.60-2.57 (m, 4H, CH₂—C═O), 2.51-2.47 (m, 4H, CH₂allylic), 2.07 (quint, J=7.5 Hz, 4H, CH₂ allylic), 1.27-1.22 (m, 3H,CH—Si), 1.08 (d, J=7.5 Hz, 18H, (CH₃)₂C), 0.97 (t, J=7.5 Hz, 6H, CH₃);¹³C NMR (125 MHz; CDCl₃) δ_(c) 170.9, 157.0, 151.4, 132.0, 129.7, 128.5,128.3, 128.2, 128.2, 128.1, 128.0, 127.9, 127.8, 127.4, 127.0, 110.9,108.0, 34.2, 25.6, 25.6, 25.5, 22.6, 20.5, 17.8, 14.2, 12.5; HRMS(ESI-TOF) m/z: [M+H]⁺ calcd. for C₅₉H₈₇O₅Si 903.6317; found 903.6321.

(4,4′,7,7′,10,10′,13,13′,16,16′,19,19′Z)-5-hydroxy-1,3-phenylenedidocosa-4,7,10,13,16,19-hexaenoate 7: Deprotection of the protectedDHA-phloroglucinol 5 (168 mg, 0.19 mmol) was performed with the generalprocedure and afforded 7 (119 mg, 86%) as an uncolored oil afterpurification on silica gel chromatography (hexane/AcOEt 90/10).

R_(f) (hexane/AcOEt 90/10) 0.19; ¹H NMR (500 MHz; CDCl₃) δ_(H) 6.48 (s,3H, CH_(aro)), 5.48-5.29 (m, 24H, CH═CH), 2.88-2.80 (m, 20H, CH₂bis-allylic), 2.60 (t, J=7.1 Hz, 4H, CH₂—C═O), 2.52-2.48 (m, 4H, CH₂allylic), 2.08 (quint, J=7.5 Hz, 4H, CH₂ allylic), 0.98 (t, J=7.5 Hz,6H, CH₃); ¹³C NMR (125 MHz; CDCl₃) δ_(c) 171.1, 156.7, 151.6, 132.0,129.8, 128.5, 128.3, 128.3, 128.2, 128.0, 128.0, 127.9, 127.8, 127.3,127.0, 107.6, 106.7, 34.2, 25.6, 25.6, 25.6, 25.5, 22.6, 20.5, 14.2;HRMS (ESI-TOF) m/z: [M+H]⁺ calcd. for C₅₀H₆₇O₅ 747.4989; found 747.4994.

(4,4′,4″,7,7′,7″,10,10′,10″,13,13′,13″,16,16′,16″,19,19′,19″Z)-benzene-1,3,5-triyl tridocosa-4,7,10,13,16,19-hexaenoate 8: Coupling of thedi-DHA-phloroglucinol 7 (108 mg, 0.14 mmol) and DHA (46 mg, 0.15 mmol)was performed with the general procedure and afforded 8 (108 mg, 73%) asan uncolored oil after purification on silica gel chromatography(hexane/AcOEt 98/2).

R_(f) (hexane/AcOEt 95/5) 0.29; ¹H NMR (500 MHz; CDCl₃) δ_(H) 6.82 (s,3H, CH_(aro)), 5.48-5.28 (m, 36H, CH═CH), 2.87-2.79 (m, 30H, CH₂bis-allylic), 2.59 (t, J=7.5 Hz, 6H, CH₂—C═O), 2.46-2.50 (m, 6H, CH₂allylic), 2.07 (quint, J=7.5 Hz, 6H, CH₂ allylic), 0.97 (t, J=7.5 Hz,9H, CH₃); ¹³C NMR (125 MHz; CDCl₃) δ_(c) 170.9, 151.4, 132.3, 130.1,128.8, 128.6, 128.5, 128.5, 128.3, 128.3, 128.2, 128.1, 127.6, 127.3,112.9, 34.5, 25.9, 25.9, 25.8, 22.8, 20.8, 14.5; HRMS (ESI-TOF-ASAP+)m/z: [M+H]⁺ calcd. for C₇₂H₉₇O₆ 1057.7280; found 1057.7285.

Example 2: Synthesis of Alkylated DHA-Phloroglucinol Conjugates

Alkylation such as methylation is one of the most abundantmetabolization of dietary (poly)phenols after ingestion. It appears thusinteresting to evaluate the impact of O-alkylation of the phenolfunction on the efficiency of the carbonyl trap action. Regarding themechanism of the chromene formation starting from phloroglucinol andtrans-retinal, O- and C-alkylation may be influenced by the introductionof such an alkyl substituent. The nucleophilicity developed by thecarbon atoms of such aromatic rings may be adjusted by the presence ofinductive electron effect and make phloroglucinol derivatives morereactive with the trans-retinal carbonyl soft-type electrophiles.

In order to access alkylated phloroglucinol-DHA, the synthesis ofmono-alkylated and mono-protected phloroglucinol 11 was investigated toallow the introduction of the lipid moiety at the latest step of thesynthetic pathway.

The difficulty in the strategy was to perform a selectivemono-alkylation and/or mono-silylation of the symmetrical phloroglucinolin the presence of phenol functions with identical reactivity. Using asolution of MeOH, or iPrOH saturated with HCl gas the mono-alkylationcould be performed starting from the phloroglucinol, in an acceptableyield lowering the proportion of dialkylated derivatives observed usingcommonly-used O-alkylation reageant such as DMS or 2-bromopropanereagent. The total protection of phloroglucinol with the TIPS protectinggroup (10), followed by the mono deprotection process, afforded thedesired mono-methytaled/isopropylated and protected phloroglucinol 11 in58% and 54% in two steps.

Using the same coupling conditions (DCC/DMAP) as for lipophenol 6,mono-alkyl and di-alkyl phloroglucinols 11 and 14 were coupled to DHAand afforded alkylated-phloroglucinol DHA conjugates 13 and 15 inexcellent to moderate yield, after removal of TIPS groups in thepresence of Et₃N-3HF for protected derivatives.

The implemented steps as mentioned above are described hereafter indetail.

5-methoxybenzene-1,3-diol 9a: To a suspension of phloroglucinol (0.40 g,3.17 mmol) in dioxane (1 mL) was added a freshly prepared solution ofMeOH saturated with dry HCl (gaz) (4 mL, 17N). The reaction was stirredat room temperature during 3 h. An additional amount of the saturatedHCl solution was added (1 mL) and the reaction was kept at 70° C. for 1h. The solvents were evaporated under vacuum and the residue obtainedwas purified by chromatography on silica gel (CH₂Cl₂/MeOH 98/2) to give9a (0.28 mg, 62%) as a white solid. The di-methylated residue 14a wasisolated in 25% yield.

R_(f) (CH₂Cl₂/MeOH 95/5) 0.47; ¹H NMR (500 MHz; MeOD) δ_(H) 5.88 (s, 3H,CH_(aro)) 3.69 (s, 3H, CH₃O); ¹³C NMR (125 MHz; CDCl₃) δ_(c) 161.7,158.1, 95.7, 94.0, 55.2; HRMS (ESI-TOF) m/z: [M−H]⁻ calcd. for C₇H₇O₃139.0395; found 139.0397.

5-isopropoxybenzene-1,3-diol 9b: To a suspension of phloroglucinol (0.40g, 3.17 mmol) in dioxane (1 mL) was added a freshly prepared solution ofiPOH saturated with dry HCl (gaz) (4 mL, 32N). The reaction was stirredat room temperature during 1 h. An additional amount of the saturatedHCl solution was added (1 mL) and the reaction was kept at 70° C. for 7h. The solvents were evaporated under vacuum and the residue obtainedwas purified by chromatography on silica gel (CH₂Cl₂/MeOH 98/2) to give9b (0.27 mg, 51%) as a white solid. The di-alkylated derivative 14b wasisolated in 13% yield.

R_(f) (CH₂Cl₂/MeOH 95/5) 0.4; ¹H NMR (500 MHz; CDCl₃) δ_(H) 5.99 (d,J=1.9 Hz, 2H, CH_(aro)), 5.96 (t, J=1.9 Hz, 1H, CH_(aro)), 5.70 (br, 2H,OH), 4.45 (quint, J=7.5 Hz, 1H, CH), 1.31 (d, J=6.0 Hz, 6H, CH3); ¹³CNMR (125 MHz; CDCl₃) δ_(c) 160.0, 158.1, 95.8, 95.5, 70.0, 22.0; HRMS(ESI-TOF) m/z: [M−H]⁻ calcd. for C₉H₁₁O₃ 167.0708; found 167.0710.

5-methoxy-1,3-bis(triisopropylsilyloxy)benzene 10a: Phloroglucinol-OMe9a (100 mg, 0.71 mmol) was dissolved in dry CH₂Cl₂ (6 mL) and dry THF(600 μl). Diisopropylethylamine (257 μl, 1.50 mmol) and TIPS-OTf (403μL, 1.50 mmol) were added dropwise to the solution and the reactionmixture was stirred at room temperature during 6 h. Additional amount ofDIPEA and TIPS-OTf were added to reach completion of the reaction. After6 h of reaction, AcOEt (15 mL) was added to the mixture and the organiclayer was washed with water (10 mL) and brine (10 mL). The organic phasewas dried (MgSO₄) and concentrated under vacuum. The residue obtainedwas purified by chromatography on silica gel (hexane/AcOEt 99/1) to givethe di-protected phloroglucinol-OMe 10a (311 mg, 96%) as an uncoloredoil.

R_(f) (hexane/AcOEt 95/5) 0.80; ¹H NMR (500 MHz; CDCl₃) δ_(H) 6.09-6.08(m, 2H, CH_(aro)), 6.07-6.06 (m, 1H, CH_(aro)), 3.73 (s, 3H, CH₃O),1.27-1.21 (m, 6H, CH—Si), 1.10 (d, J=7.0 Hz, 36H, (CH₃)₂C); ¹³C NMR (125MHz; CDCl₃) δ_(c) 161.3, 157.8, 105.0, 99.7, 55.5, 18.2, 13.0; HRMS(ESI-TOF) m/z: [M+H]⁺ calcd. for C₂₅H₄₉O₃Si₂ 453.3214; found 453.3226.

5-isopropoxy-1,3-bis(triisopropylsilyloxy)benzene 10b:Phloroglucinol-OiP 9b (231 mg, 1.37 mmol) was dissolved in dry CH₂Cl₂(24 mL). Diisopropylethylamine (617 μl, 3.60 mmol) and TIPS-OTf (969 μL,3.60 mmol) were added dropwise to the solution and the reaction mixturewas stirred at room temperature during 6 h. AcOEt (30 mL) were added tothe mixture and the organic layer was washed with water (15 mL) andbrine (15 mL). The organic phase was dried (MgSO₄) and concentratedunder vacuum. The residue obtained was purified by chromatography onsilica gel (hexane/AcOEt 99.5/0.5) to give the di-protectedphloroglucinol-OiP 10b (573 mg, 87%) as an uncolored oil.

R_(f) (hexane/AcOEt 95/5) 0.88; ¹H NMR (500 MHz; CDCl₃) δ_(H) 6.07-6.06(m, 2H, CH_(aro)), 6.04-6.02 (m, 1H, CH_(aro)), 4.42 (quint, J=6.0 Hz,1H, CH_(ip)), 1.29 (d, J=6.0 Hz, (CH₃)₂C_(ip)), 1.26-1.19 (m, 6H,CH—Si), 1.09 (d, J=6.0 Hz, 36H, (CH₃)₂C_(TIPS)); ¹³C NMR (125 MHz;CDCl₃) δ_(c) 159.5, 157.7, 105.0, 101.9, 70.2, 22.3, 18.2, 12.9; HRMS(ESI-TOF) m/z: [M+H]⁺ calcd. for C₂₇H₅₃O₃Si₂ 481.3527; found 481.3537.

3-methoxy-5-(triisopropylsilyloxy)phenol 11a: The di-protectedphloroglucinol 10a (92 mg, 0.19 mmol) was dissolved in dry THF (6.50mL). Et₃N-3HF (33 μL, 0.19 mmol) was added dropwise and the reaction wasfollowed by TCL and stopped in order to reduce as much as possible theproportion of the fully deprotected derivative. After 7 h of stirring atroom temperature, AcOEt (15 mL) was added to the mixture and the organiclayer was washed with water (10 mL) and brine (10 mL). The organic phasewas dried (MgSO₄) and concentrated under vacuum. The residue obtainedwas purified by chromatography on silica gel (hexane/AcOEt 95/5 to70/30) to give the mono-protected phloroglucinol 11a (37 mg, 61%) as awhite solid. The fully deprotected derivative was isolated in 11% (3.20mg).

R_(f) (hexane/AcOEt 70/30) 0.6; ¹H NMR (500 MHz; CDCl₃) δ_(H) 6.05 (s,1H, CH_(aro)), 6.02-6.00 (m, 2H, CH_(aro)), 4.86 (br, 1H, OH), 3.73 (s,3H, CH₃O), 1.29-1.20 (m, 3H, CH—Si), 1.09 (d, J=7.5 Hz, 18H, (CH₃)₂C);¹³C NMR (125 MHz; CDCl₃) δ_(c) 161.3, 157.9, 157.2, 100.1, 98.8, 94.6,55.2, 17.9, 12.6; HRMS (ESI-TOF) m/z: [M−H]⁻ calcd. for C₁₆H₂₇O₃Si295.1729; found 295.1730.

3-isopropoxy-5-(triisopropylsilyloxy)phenol 11b: The di-protectedphloroglucinol 10b (100 mg, 0.21 mmol) was dissolved in dry THF (6 mL).Et₃N-3HF (68 μL, 0.42 mmol) was added to the mixture and the reactionwas followed by TLC and stopped in order to reduce as much as possiblethe formation on the fully deprotected derivative. After 5 h of stirringat room temperature, 15 mL of AcOEt were added to the mixture and theorganic layer was washed with water (10 mL) and brine (10 mL). Theorganic phase was dried (MgSO₄) and concentrated under vacuum. Theresidue obtained was purified by chromatography on silica gel(hexane/AcOEt 95/5) to give the mono-protected phloroglucinol 11b (42mg, 62%) as uncolored oil. The fully deprotected derivative was isolatedin 14% (5 mg).

R_(f) (hexane/AcOEt 70/30) 0.7; ¹H NMR (500 MHz; CDCl₃) δ_(H) 6.04 (t,J=2.5 Hz, 1H, CH_(aro)), 6.01 (t, J=2.5 Hz, 1H, CH_(aro)), 5.99 (t,J=2.5 Hz, 1H, CH_(aro)), 4.87 (br, 1H, OH), 4.44 (quint, J=6.0 Hz, 1H,CH_(ip)), 1.31 (d, J=6.0 Hz, 6H, (CH₃)₂C_(ip)), 1.28-1.20 (m, 3H,CH—Si), 1.10 (d, J=7.5 Hz, 18H, (CH₃)₂C_(TIPS)); ¹³C NMR (125 MHz;CDCl₃) δ_(c) 159.6, 157.9, 157.0, 100.7, 100.0, 96.6, 70.0, 22.0, 17.9,12.6; HRMS (ESI-TOF) m/z: [M−H]⁻ calcd. for C₁₈H₃₁O₃Si 323,2042; found323.2045.

(4,7,10,13,16,19 Z)-3-methoxy-5-(triisopropylsilyloxy)phenyl docosa-4,7,10,13,16,19-hexaenoate 12a: Coupling of the protectedphloroglucinol-OMe 11a (96 mg, 0.32 mmol) and DHA (106 mg, 0.32 mmol)following the general procedure, afforded 12a (120 mg, 60%) as auncolored oil after purification on silica gel chromatography(hexane/AcOEt 99/1).

R_(f) (hexane/ AcOEt 99/1) 0.28; ¹H NMR (500 MHz; CDCl₃) δ_(H) 6.30 (s,1H, CH_(aro)), 6.25-6.23 (m, 2H, CH_(aro)), 5.48-5.28 (m, 12H, CH═CH),3.74 (s, 3H, CH₃O), 2.87-2.79 (m, 10H, CH₂ bis-allylic), 2.60-2.57 (m,2H, CH₂—C═O), 2.52-2.48 (m, 2H, CH₂ allylic), 2.07 (quint, J=7.5 Hz, 2H,CH₂ allylic), 1.29-1.20 (m, 3H, CH—Si), 1.09 (d, J=7.4 Hz, 18H,(CH₃)₂C), 0.97 (t, J=7.5 Hz, 3H, CH₃); ¹³C NMR (125 MHz; CDCl₃) δ_(c)171.2, 160.8, 157.4, 152.0, 132.0, 129.6, 128.5, 128.3, 128.2, 128.2,128.1, 128.1, 128.0, 127.8, 127.5, 127.0, 106.3, 103.8, 100.4, 55.4,34.3, 25.6, 25.6, 25.5, 22.7, 20.5, 17.8, 14.2, 12.6; HRMS (ESI-TOF)m/z: [M+H]⁺ calcd. for C₃₈H₅₉O₄Si 607.4183; found 607.4185.

(4,7,10,13,16,19 Z)-3-isopropoxy-5-(triisopropylsilyloxy)phenyldocosa-4,7,10,13,16,19-hexaenoate 12b: Coupling of themono-TIPS-mono-isopropyl-phloroglucinol 11b (100 mg, 0.31 mmol) and DHA(101 mg, 0.31 mmol) was performed with the general procedure andafforded 12b (132 mg, 67%) as an uncolored oil after purification onsilica gel chromatography (hexane/AcOEt 99/1).

R_(f) (hexane/AcOEt 99/1) 0.30; ¹H NMR (500 MHz; CDCl₃) δ_(H) 6.29 (t,J=2.0 Hz,1H, CH_(aro)), 6.24 (t, J=2.0 Hz,1H, CH_(aro)), 6.21 (t, J=2.0Hz,1H, CH_(aro)), 5.49-5.29 (m, 12H, CH═CH), 4.45 (quint, J=6.0 Hz, 1H,CH_(ip)), 2.88-2.81 (m, 10H, CH₂ bis-allylic), 2.60-2.57 (m, 2H,CH₂—C═O), 2.52-2.48 (m, 2H, CH₂ allylic), 2.08 (quint, J=7.5 Hz, 2H, CH₂allylic), 1.32 (d, J=6.0 Hz, 6H, (CH₃)₂C_(ip)), 1.28-1.22 (m, 3H,CH—Si), 1.10 (d, J=7.5 Hz, 18H, (CH₃)₂C_(TIPS)), 0.98 (t, J=7.5 Hz, 3H,CH₃); ¹³C NMR (125 MHz; CDCl₃) δ_(c) 171.1, 159.1, 157.3, 151.9, 132.0,129.6, 128.5, 128.3, 128.2, 128.2, 128.1, 128.0, 128.0, 127.8, 127.6,127.0, 106.0, 105.3, 102.3, 70.1, 34.3, 25.6, 25.6, 25.5, 22.7, 21.9,20.5, 17.9, 14.2, 12.6; HRMS (ESI-TOF) m/z: [M+H]⁺ calcd. for C₄₀H₆₃O₄Si635.4496; found 635.4502.

(4,7,10,13,16,19 Z)-3-hydroxy-5-methoxyphenyl docosa-4,7,10,13,16,19-hexaenoate 13a: Deprotection of the protected DHA-phloroglucinol-OMe12a (75 mg, 0.12 mmol) was performed with the general procedure andafforded 13a (49 mg, 88%) as an uncolored oil after purification onsilica gel chromatography (hexane/AcOEt 90/10).

R_(f) (hexane/AcOEt 80/20) 0.29; ¹H NMR (500 MHz; CDCl₃) δ_(H) 6.25 (s,1H, CH_(aro)), 6.22 (s, 1H, CH_(aro)), 6.18 (s, 1H, CH_(aro)), 5.49-5.28(m, 12H, CH═CH), 5.21 (br, 1H, OH), 3.75 (s, 3H, CH₃O), 2.88-2.80 (m,10H, CH₂ bis-allylic), 2.60 (t, J=7.3 Hz, 2H, CH₂—C═O), 2.52-2.46 (m,2H, CH₂ allylic), 2.07 (quint, J=7.3 Hz, 2H, CH₂ allylic), 0.97 (t,J=7.5 Hz, 3H, CH₃); ¹³C NMR (125 MHz; CDCl₃) δ_(c) 171.8, 161.2, 157.2,152.0, 132.0, 129.7, 128.5, 128.3, 128.2, 128.2, 128.0, 128.0, 127.9,127.8, 127.4, 127.0, 101.9, 100.0, 99.4, 34.3, 25.6, 25.6, 25.5, 22.7,20.5, 14.2; HRMS (ESI-TOF) m/z: [M+H]⁺ calcd. for C₂₉H₃₉O₄ 451.2848;found 451.2851.

(4,7,10,13,16,19 Z)-3-hydroxy-5-isopropoxyphenyl docosa-4,7,10,13,16,19-hexaenoate 13b: Deprotection of the protectedDHA-phloroglucinol 12b (120 mg, 0.19 mmol) was performed through thegeneral procedure and afforded 13b (82 mg, 90%) as an uncolored oilafter purification on silica gel chromatography (hexane/AcOEt 90/10).

R_(f) (hexane/AcOEt 90/10) 0.30; ¹H NMR (500 MHz; CDCl₃) δ_(H) 6.25 (t,J=2.0 Hz, 1H, CH_(aro)), 6.21 (t, J=2.0 Hz, 1H, CH_(aro)), 6.17 (t,J=2.0 Hz,1H, CH_(aro)), 5.48-5.29 (m, 12H, CH═CH), 4.95 (br, 1H, OH),4.47 (quint, J=6.0 Hz, 1H, CH_(ip)), 2.89-2.81 (m, 10H, CH₂bis-allylic), 2.61-2.58 (m, 2H, CH₂—C═O), 2.54-2.48 (m, 2H, CH₂allylic), 2.08 (quint, J=7.5 Hz, 2H, CH₂ allylic), 1.32 (d, J=6.0 Hz,6H, (CH₃)₂C_(ip)), 0.98 (t, J=7.5 Hz, 3H, CH₃); ¹³C NMR (125 MHz; CDCl₃)δ_(c) 171.3, 159.6, 156.9, 152.1, 132.0, 129.7, 128.5, 128.3, 128.3,128.2, 128.1, 128.0, 128.0, 127.8, 127.5, 127.0, 101.9, 101.5, 100.8,70.2, 34.3, 25.6, 25.6, 25.6, 25.5, 22.7, 21.9, 20.5, 14.2; HRMS(ESI-TOF) m/z: [M−H]⁻ calcd. for C₃₁H₄₁O₄ 477.3005; found 477.3007.

(4,7,10,13,16,19 Z)-3,5-dimethoxyphenyldocosa-4,7,10,13,16,19-hexaenoate 15a: Coupling of thedi-OMe-phloroglucinol 14a (47 mg, 0.30 mmol) and DHA (100 mg, 0.30 mmol)was performed with the general procedure and afforded 15a (110 mg, 77%)as an uncolored oil after purification on silica gel chromatography(hexane/AcOEt 97/3).

R_(f) (hexane/AcOEt 95/5) 0.36; ¹H NMR (500 MHz; CDCl₃) δ_(H) 6.33 (t,J=2.0 Hz, 1H, CH_(aro)), 6.25 (d, J=2.0 Hz, 2H, CH_(aro))_(,) 5.49-5.28(m, 12H, CH═CH), 3.76 (s, 6H, s CH₃O), 2.88-2.79 (m, 10H, CH₂bis-allylic), 2.60 (t, J=7.3 Hz, 2H, CH₂—C═O), 2.54-2.49 (m, 2H, CH₂allylic), 2.07 (quint, J=7.3 Hz, 2H, CH₂ allylic), 0.97 (t, J=7.5 Hz,3H, CH₃); ¹³C NMR (125 MHz; CDCl₃) δ_(c) 171.4, 161.0, 152.1, 131.9,129.8, 128.5, 128.3, 128.2, 128.2, 128.0, 128.0, 127.9, 127.8, 127.4,126.9, 100.1, 98.1, 55.4, 34.3, 25.6, 25.5, 25.4, 22.7, 20.4, 14.2; HRMS(ESI-TOF) m/z: [M+H]⁺ calcd. for C₃₀H₄₁O₄ 465.3005; found 465.3011.

(4,7,10,13,16,19 Z)-3,5-diisopropoxyphenyl docosa-4,7,10,13,16,19-hexaenoate 15b: Coupling of the di-OiP-phloroglucinol 14b (96 mg,0.45 mmol) and DHA (150 mg, 0.45 mmol) was performed with the generalprocedure and afforded 15b (168 mg, 70%) as an uncolored oil afterpurification on silica gel chromatography (hexane/AcOEt 97/3).

R_(f), (hexane/AcOEt 95/5) 0.57; ¹H NMR (500 MHz; CDCl₃) δ_(H) 6.28 (s,1H, CH_(aro)), 6.19 (s, 2H, CH_(aro)), 5.48-5.28 (m, 12H, CH═CH), 4.46(quint, J=5.9 Hz, 2H, CH), 2.89-2.78 (m, 10H, CH₂ bis-allylic), 2.59 (t,J=7.4 Hz, 2H, CH₂—C═O), 2.53-2.48 (m, 2H, CH₂ allylic), 2.07 (quint,J=7.3 Hz, 2H, CH₂ allylic), 1.31 (d, J=6.0 Hz, 12H, (CH₃)₂C), 0.97 (t,J=7.5 Hz, 3H, CH₃); ¹³C NMR (125 MHz; CDCl₃) δ_(c) 171.2, 159.3, 152.1,131.9, 129.6, 128.5, 128.3, 128.2, 128.2, 128.0, 128.0, 127.9, 127.8,127.5, 126.9, 101.4, 101.2, 70.0, 34.2, 25.6, 25.5, 25.4, 22.7, 21.9,20.5, 14.2; HRMS (ESI-TOF) m/z: [M+H]⁺ calcd. for C₃₄H₄₉O₄ 521.3631;found 521.3636.

Example 2-1: Synthesis of Propyl-DHA-Phloroglucinol Conjugate

5-propylbenzene-1,3-diol (9c): To a suspension of phloroglucinol (0.40g, 3.17 mmol) in dioxane (1 mL) was added a prepared solution ofPropanol saturated with dry HCl (gaz) (4 mL). The reaction was stirredat room temperature during 4 h. An additional amount of the saturatedHCl solution was added (1 mL) and the reaction was kept at 70° C. for 1h. The solvents were evaporated under vacuum and the residue obtainedwas purified by chromatography on silica gel (CH₂Cl₂/MeOH 98/2) to give9c (154 mg, 65%) as a white solid.

R_(F) (CH₂CI₂/MeOH 95/5) 0.6; ¹H NMR (500 MHz; MeOD) δ_(H) 5.87 (s, 3H,CH_(aro)), 4.89 (br, 2H, OH), 3.82 (t, J=6.5 Hz, 2H, CH₂—O), 1.74 (sex,J=7.2 Hz, 2H, CH₂—C), 1.01 (t, J=7.5 Hz, 3H, CH₃).

5-propyl-1,3-bis(triisopropylsilyloxy)benzene (10c):Phloroglucinol-OPropyl 9c (300 mg, 1.78 mmol) was dissolved in dryCH₂Cl₂ (30 mL). Diisopropylethylamine (641 μl, 3.75 mmol) and TIPS-OTf(1.01 mL, 3.75 mmol) were added dropwise to the solution and thereaction mixture was stirred at room temperature during 3 h. AcOEt (30mL) was added to the mixture and the organic layer was washed with water(20 mL) and brine (20 mL). The organic phase was dried (MgSO₄) andconcentrated under vacuum. The residue obtained was purified bychromatography on silica gel (Pentane/AcOEt 99.5/0.5) to give thedi-protected phloroglucinol-OPropyl 10c (402 mg, 47%) as an uncoloredoil, with was directly engaged in the selective monodeprotection.

3-propyl-5-(triisopropylsilyloxy)phenol (11c): The di-protectedphloroglucinol 10c (400 mg, 0.83 mmol) was dissolved in dry THF (30 mL).Et₃N-3HF (277 μL, 1.66 mmol) was added dropwise and the reaction wasfollowed by TCL and stopped in order to reduce as much as possible theproportion of the fully deprotected derivative. After 7 h of stirring atroom temperature, AcOEt (30 mL) was added to the mixture and the organiclayer was washed with water (20 mL) and brine (20 mL). The organic phasewas dried (MgSO₄) and concentrated under vacuum. The residue obtainedwas purified by chromatography on silica gel (pentane/AcOEt 97/3) togive the mono-protected phloroglucinol 11c (137 mg, 51%) as a white oil.

R_(f) (hexane/AcOEt 9.5/0.5) 0.5; ¹H NMR (500 MHz; CDCl₃) δ_(H) 6.04 (t,J=2.5 Hz, 1H, CH_(aro)), 6.01 (t, J=2 Hz, 1H, CH_(aro)), 5.98 (t, J=2Hz, 1H, CH_(aro)), 4.63 (br, 1H, OH), 3.83 (t, J=6.5 Hz, 2H, CH₂O),1.76(sext, J=7 Hz, 2H, CH₂—C), 1.27-1.20 (m, 3H, CH—Si), 1.09 (d, J=7 Hz,18H, (CH₃)₂C), 1.01 (t, J=7.5 Hz, 3H, CH₃).

(4,7,10,13,16,19Z)-3-propoxy-5-((triisopropylsilyl)oxy)phenyldocosa-4,7,10,13,16,19-hexaenoate (12c)

Coupling of the mono-protected phloroglucinol-propyl 11c (100 mg, 0.30mmol) and DHA (109 mg, 0.33 mmol) was performed with the generalprocedure and afforded 12c (96 mg, 50%) as a yellow oil afterpurification on silica gel chromatography (Hexane/AcOEt 99/1).

R_(f) (Hexane/AcOEt 95/5) 0.45; ¹H NMR (500 MHz, CDCl₃) δ 6.31 (t,J=2.2, 1H), 6.26 (t, J=2.1, 1H), 6.23 (t, J=2.1, 1H), 5.54-5.26 (m,12H), 3.85 (t, J=6.6, 2H), 2.93-2.77 (m, 10H), 2.61-2.58 (m, 2H),2.55-2.47 (m, 2H), 2.14-2.02 (m, 2H), 1.80-1.75 (m, 4H), 1.32-1.20 (m,6H), 1.11 (d, J=7.3, 18H), 1.02 (t, J=7.4, 3H), 0.98 (t, J=7.5, 3H); ¹³CNMR (126 MHz, CDCl₃) δ 171.34, 160.51, 157.45, 152.05, 132.12, 129.74,128.66, 128.44, 128.37, 128.36, 128.20, 128.19, 128.18, 128.12, 127.99,127.70, 127.13, 106.14, 104.32, 101.16, 69.73, 34.42, 25.76, 25.74,25.65, 22.90, 22.61, 18.01, 18.00, 14.40, 12.73, 10.62.

(4,7,10,13,16,19Z)-3-hydroxy-5-propoxyphenyl docosa-4,7,10,13,16,19-hexaenoate (13c)

Deprotection of the protected DHA-phloroglucinol-propyl 12c (95 mg, 0.14mmol) was performed with the general procedure and afforded 13c (58 mg,87%) as an uncoloured oil after 4h30 of reaction and purification onsilica gel chromatography (Cyclohexane/AcOEt 95/5).

R_(f) (Hexane/AcOEt 90/10) 0.21; ¹H NMR (500 MHz, CDCl₃) δ 6.23 (m, 1H),6.20 (m, 1H), 6.15 (m, 1H), 5.52-5.27 (m, 12H), 3.83 (t, J=6.5, 2H),2.92-2.78 (m, 10H), 2.66-2.57 (m, 1H), 2.57-2.47 (m, 2H), 2.09-2.06 (m,3H), 1.79-1.73 (m, 3H), 1.03-0.95 (m, 6H); ¹³C NMR (126 MHz, CDCl₃) δ172.12, 160.87, 157.37, 152.07, 132.17, 129.88, 128.69, 128.48, 128.40,128.38, 128.20, 128.20, 128.09, 128.00, 127.55, 127.14, 101.79, 100.66,100.02, 69.84, 34.44, 25.75, 25.73, 22.87, 22.54, 20.67, 14.39, 10.58.

Example 3: Synthesis of DHA-Resveratrol Conjugate

As presented above, the trapping mechanism of a carbonyl stressor (AtR)by the phloroglucinol would require the presence of a resorcinol patternon the phenolic backbone. Such a framework is found in many othernaturally occurring polyphenols (ring A of flavonoids, for instance),but also in stilbenoids and especially in resveratrol, which is aperfect vinylogous of phloroglucinol. Because of the importance of theresorcinol reactivity to scavenge AtR, DHA was linked to the hydroxyl atthe 4′ position of resveratrol, to let 3- and 5-hydroxyl groupsavailable to form the chromene derivative. Compared to phloroglucinolseries, the strategy envisaged for the stilbenoid synthesis presentsadditional difficulties since it requires a selective protection of thephenol at the 3 and 5 positions, despite the close reactivity of thethree hydroxyl groups of resveratrol. To overcome this drawback,resveratrol was regio-selectively acylated by Candida antartica lipase B(CALB or Novozyme 435, which present high selectivity for the hydroxylgroup at the 4′-position) in the presence of vinyl acetate to afford asingle protected product, the 4′-O-acetylresveratrol 16, in 57%.Hydroxyls at positions 3 and 5 were protected using TIPS-OTf to obtained17 which was subjected to acetyl deprotection in the presence of amethanolic solution of MeONa in excellent yield. The 4′-deprotectedresveratrol 18 was then coupled to DHA (19), as performed in thephloroglucinol series, and subjected to TIPS deprotection to affordresveratrol-DHA 20 with 20% overall yield.

The implemented steps as mentioned above are described hereafter indetail.

(E)-4-(3,5-dihydroxystyryl)phenyl acetate 16: Resveratrol (200 mg, 0.88mmol) was dissolved in 2-methylbutan-2-ol (20 mL) and vinyl acetate (5mL) in presence of the supported lipase Candida Antarctica (Novozyme435, CalB, 1 g). The mixture was stirred with a rotary evaporator at 40°C. during 4 days. The lipase was filtered off and washed with AcOEttwice and diethyl ether. The filtrate obtained was concentrated underreduced pressure and the residue obtained was purified by chromatographyon silica gel (CH₂Cl₂/MeOH 99/1 to 90/10) to give the 4′-O-acetylresveratrol 16 (135 mg, 57%) as white solid. 27% of starting materialwere recovered after purification (5 mg).

R_(f) (CH₂Cl₂/MeOH 95/5) 0.30; ¹H NMR (500 MHz; CD₃OD) δ_(H) 7.54 (d,J=7.6 Hz, 2H, H_(2′) and H_(6′)), 7.07 (d, J=7.6 Hz, 2H, H_(3′) andH_(5′)) 7.04 (d, J=16.2 Hz, 1H, H₈), 6.97 (d, J=16.2 Hz, 1H, H₇), 6.49(s, 2H, H₂, H₆), 6.21-6.19 (m, 1H, H₄), 2.27 (s, 3H, CH_(3(OAc))); ¹³CNMR (125 MHz; MeOD) δ_(c) 171.1, 159.7, 151.5, 140.6, 136.58, 130.24,128.3, 128.3, 122.9, 106.1, 103.2, 20.9; HRMS (ESI-TOF) m/z: [M+H]⁺calcd. for C₁₆H₁₅O₄ 271.0964; found 271.0972.

(E)-4-(3,5-bis(triisopropylsilyloxy)styryl)phenyl acetate 17:Resveratrol-4′-OAc 16 (100 mg, 0.37 mmol) was dissolved in dry THF (6mL). Triethylamine (109 μL, 0.78 mmol) and TIPS-OTf (208 μL, 0.78 mmol)were added dropwise to the solution and the reaction mixture was stirredat room temperature during 2 h. A same amount of Et₃N and TIPS-OTf wereadded to reach completion of the reaction. After 3 additional hours ofreaction, the solvent was evaporated under reduced pressure. The residueobtained was dissolved in 10 mL of AcOEt and washed with water (10 mL)and brine (10 mL). The organic phase was dried (MgSO₄) and concentratedunder vacuum. The residue obtained was purified by chromatography onsilica gel (pentane/AcOEt 80/20) to give the protected resveratrol 17(152 mg, 71%) as an uncolored oil.

R_(f) (pentane/AcOEt 95/5) 0.5; ¹H NMR (500 MHz; CDCl₃) δ_(H) 7.51 (d,J=8.0 Hz, 2H, H_(2′) and H_(6′)), 7.09 (d, J=8.0 Hz, 2H, H_(3′) andH_(5′)), 6.98 (d, J=16.3 Hz, 1H, H₈), 6.92 (d, J=16.3 Hz, 1H, H₇), 6.65(s, 2H, H₂, H₆), 6.37-6.36 (m, 1H, H₄), 2.31 (s, 3H, CH_(3(OAc))), 1.26(m, 6H, CH—Si), 1.12 (d, J=7.6 Hz, 36H, (CH₃)₂C); ¹³C NMR (125 MHz;CDCl₃) δ_(c) 169.7, 157.3, 150.2, 139.0, 135.3, 129.3, 127.8, 127.7,122.0, 111.6, 111.5, 21.4, 18.2, 13.9; HRMS (ESI-TOF) m/z: [M+H]⁺ calcd.for C₃₄H₅₅O₄Si₂ 583.3633; found 583.3640.

(E)-4-(3,5-bis(triisopropylsilyloxy)styryl)phenol 18: The protectedresveratrol 17 (239 mg, 0.41 mmol) was dissolved in dry MeOH (2 mL) andCH₂Cl₂ (1 mL). A catalytic amount of sodium methanolate (6.60 mg, 0.12mmol) was added to the solution and the reaction mixture was stirred atroom temperature during 2 h. An amount of NaOMe was added to reachcompletion of the reaction. After 5 h of reaction, the solvent wasevaporated under reduced pressure. The residue obtained was purified bychromatography on silica gel (Hexane/AcOEt 95/5) to give the4′-deprotected resveratrol 18 (214 mg, 97%) as an uncolored oil.

R_(f) (hexane/AcOEt 90/10) 0.41; ¹H NMR (500 MHz; CD₃OD) δ_(H) 7.38 (d,J=8.5 Hz, 2H, H_(2′) and H_(6′)), 6.95 (d, J=16.2 Hz, 1H, H₈), 6.84 (d,J=16.2 Hz, 1H, H₇), 6.77 (d, J=8.5 Hz, 2H, H_(3′) and H_(5′)), 6.64-6.63(m, 2H, H₂, H₆), 6.30-6.29 (m, 1H, H₄), 1.30-1.22 (m, 6H, CH—Si), 1.14(d, J=7.5 Hz, 36H, (CH₃)₂C); ¹³C NMR (125 MHz; MeOD) δ_(c)158.5, 158.3,141.3, 130.1, 129.9, 129.0, 126.5, 116.5, 112.1, 111.4, 18.4, 13.9; HRMS(ESI-TOF) m/z: [M+H]⁺ calcd. for C₃₂H₅₃O₃Si₂ 541.3527; found 541.3536.

(4,7,10,13,16,19 Z)-4-((E)-3,5-bis(triisopropylsilyloxy)styryl)phenyldocosa-4,7,10,13,16,19-hexaenoate 19: Coupling of the di-protectedresveratrol 18 (103 mg, 0.18 mmol) and DHA (67 mg, 0.20 mmol) wasperformed with the general procedure and afforded 19 (130 mg, 80%) as anuncolored oil after purification on silica gel chromatography(hexane/AcOEt 99/1).

R_(f) (hexane/AcOEt 95/5) 0.73; ¹H NMR (500 MHz; CDCl₃) δ_(H) 7.50 (d,J=8.5 Hz, 2H, H_(2′) and H_(6′)), 7.07 (d, J=8.4 Hz, 2H, H_(3′) andH_(5′)), 6.98 (d, J=16.5 Hz, 1H, H₈), 6.92 (d, J=16.5 Hz, 1H, H₇), 6.64(d, J=2.3 Hz, 2H, H₂, H₆), 6.36 (t, J=2.3 Hz 1H, H₄), 5.50-5.29 (m, 12H,CH═CH), 2.90-2.80 (m, 10H, CH₂ bis-allylic), 2.64 (t, J=7.0 Hz, 2H,CH₂—C═O), 2.55-2.51 (m, 2H, CH₂ allylic), 2.08 (quint, J=7.0 Hz, 2H,CH₂allylic), 1.29-1.22 (m, 6H, CH—Si), 1.12 (d, J=7.5 Hz, 36H, (CH₃)₂C);0.98 (t, J=7.5 Hz, 3H, CH₃); ¹³C NMR (125 MHz; CDCl₃) δ_(c) 171.8,157.4, 150.4, 139.1, 135.3, 132.3, 130.0, 129.3, 128.9, 128.7, 128.6,128.6, 128.4, 128.4, 128.3, 128.2, 127.9, 127.8, 127.7, 127.3, 122.0,111.7, 111.6, 34.6, 25.9, 25.9, 25.8, 23.1, 20.9, 18.2, 14.6, 13.0; HRMS(ESI-TOF) m/z: [M+H]⁺ calcd. for C₅₄H₈₃O₄Si₂ 851.5824; found 851.5825.

(4,7,10,13,16,19 Z)-4-((E)-3,5-dihydroxyphenylstyryl)phenyl docosa-4,7,10,13,16,19-hexaenoate 20: Deprotection of the protectedDHA-resveratrol 19 (142 mg, 0.17 mmol) was performed with the generalprocedure and afforded 20 (55 mg, 61%) as white solid after 7 h ofreaction and purification on silica gel chromatography (hexane/AcOEt95/5 to 70/30).

R_(f) (hexane/AcOEt 70/30)=0.22; ¹H NMR (500 MHz; CDCl₃) δ_(H) 7.45 (d,J=8.6 Hz, 2H, H_(2′) and H_(6′)), 7.07 (d, J=8.5 Hz, 2H, H_(3′) andH_(5′)), 6.95 (d, J=16.2 Hz, 1H, H₈), 6.85 (d, J=16.2 Hz, 1H, H₇), 6.51(d, J=2.1 Hz, 2H, H₂, H₆), 6.26 (t, J=2.1 Hz, 1H, H₄), 5.52-5.29 (m,12H, CH₂ bis-allylic), 5.13 (br, 2H, OH), 2.90-2.80 (m, 10H, CH₂allylic), 2.66 (t, J=7.4 Hz, 2H, CH₂—C═O), 2.52-2.56 (m, 2H, CH₂allylic), 2.08 (quint, J=7.8 Hz, 2H, CH₂ allylic), 0.98 (t, J=7.3 Hz,3H, CH₃); ¹³C NMR (125 MHz; CDCl₃) δ_(c) 172.3, 157.3, 150.4, 140.0,135.2, 132.4, 130.1, 128.9, 128.7, 128.6, 128.6, 128.6, 128.5, 128.4,128.4, 128.3, 128.2, 127.8, 127.7, 127.3, 122.1, 106.4, 102.7, 34.6,25.9, 25.8, 23.1, 20.9, 14.6; HRMS (ESI-TOF) m/z: [M+H]⁺ calcd. forC₃₆H₄₃O₄ 539.3155; found 539.3160.

Example 3-1: Synthesis of DHA-Resveratrol Conjugate at the 3 Position

(E)-4-(3-hydroxy-5-((triisopropylsilyl)oxy)styryl)phenyl acetate (26)

The protected resveratrol 17 (1 g, 1.7 mmol) of Example 3 was dissolvedin dry THF (60 mL), was added dropwise triethylammonium trihydrofluoride(554 μL, 3.4 mmol). The reaction was stirred at room temperature during3 h. AcOEt (60 mL) was added to the mixture and the organic layer waswashed with water (20 mL) and brine (20 mL). The organic phase was driedon MgSO₄ and concentrated under vacuum. The residue obtained waspurified by chromatography on silica gel (Cyclohexane/AcOEt 95/5 to80/20) to give the mono-protected resveratrol 26 (350 mg, 48%) as awhite solid. The di-protected resveratrol was isolated in 26% as a whitesolid (118 mg).

R_(f) (Hexane/AcOEt 70/30) 0.6; ¹H NMR (500 MHz, CDCl₃) δ 7.48 (d, J=8.5Hz, 2H), 7.08 (d, J=8.5 Hz, 2H), 6.92 (q, J=15.0 Hz, 2H), 6.59 (s, 1H),6.55 (s, 1H), 6.32 (t, J=2.2 Hz, 1H), 5.35 (s, 1H), 2.32 (s, 3H),1.33-1.22 (m, 3H), 1.12 (d, J=7.3 Hz, 18H); ¹³C NMR (126 MHz, CDCl₃) δ170.23, 157.52, 156.89, 150.06, 139.24, 135.21, 128.88, 127.92, 127.61,121.85, 111.26, 107.01, 106.28, 21.30, 18.06, 12.78.

(4,7,10,13,16,19Z)-3-((E)-4-acetoxystyryl)-5-((triisopropylsilyl)oxy)phenyldocosa-4,7,10,13,16,19-hexaenoate (27)

Coupling of the mono-protected resveratrol 26 (470 mg, 1.1 mmol) and DHA(397 mg, 1.2 mmol) was performed with the general procedure and afforded27 (391 mg, 49%) as a white solid after purification on silica gelchromatography (Cyclohexane/AcOEt 98/2).

R_(f) (Hexane/AcOEt 90/10) 0.5; ¹H NMR (500 MHz, CDCl₃) δ 7.49 (d, J=8.7Hz, 2H), 7.08 (d, J=8.6 Hz, 2H), 6.97 (q, J=16.2 Hz, 2H), 6.85 (t, J=1.9Hz, 2H), 6.53 (t, J=2.1Hz, 1H), 5.54-5.22 (m, 12H), 2.93-2.76 (m, 10H),2.63-2.60 (m, 2H), 2.58-2.49 (m, 2H), 2.13-2.01 (m, 2H), 1.56 (s, 3H),1.31-1.25 (m, 3H), 1.12 (d, J=7.3, 18H), 0.97 (t, J=7.5, 3H); ¹³C NMR(126 MHz, CDCl₃) δ 171.44, 169.55, 157.06, 151.81, 150.32, 139.23,134.91, 132.15, 129.80, 128.70, 128.67, 128.48, 128.39, 128.38, 128.28,128.20, 128.18, 128.11, 127.99, 127.68, 127.66, 127.13, 121.93, 115.79,112.89, 112.26, 34.45, 25.77, 25.76, 25.74, 25.65, 22.90, 21.27, 20.68,18.04, 14.41, 12.75.

(4,7,10,13,16,19Z)-3-((E)-4-hydroxystyryl)-5-((triisopropylsilyl)oxy)phenyldocosa-4,7,10,13,16,19-hexaenoate (28)

The protected DHA-resveratrol 27 (345 mg, 0.47 mmol) was dissolved int-butylmethylether (55 mL) and n-BuOH (2 mL). The supported lipaseCandida Antarctica (Novozyme 435, CalB, 345 mg) was added to thissolution and the mixture was stirred with a rotary evaporator at 40° C.during 3 days. The lipase was filtered off and washed with 5×30 mL AcOEtand 2×30 mL diethyl ether. The filtrate obtained was concentrated underreduced pressure and the residue obtained was purified by chromatographyon silica gel (Cyclohexane/AcOEt 95/5 to 90/10) to give the compound 28(291 mg, 89%) as a yellow oil.

R_(f) (Hexane/AcOEt 90/10) 0.55; ¹H NMR (500 MHz, CDCl₃) δ 7.37 (d,J=8.6 Hz, 2H), 6.96 (d, J=16.2 Hz, 1H), 6.88-6.78 (m, 5H), 6.50 (t,J=2.1 Hz, 1H), 5.52-5.26 (m, 12H), 2.95-2.74 (m, 10H), 2.67-2.59 (m,2H), 2.54-2.52 (m, 2H), 2.14-2.00 (m, 2H), 1.34-1.20 (m, 3H), 1.11 (d,J=7.3 Hz, 18H), 0.97 (t, J=7.5 Hz, 3H); ¹³C NMR (126 MHz, CDCl₃) δ171.54, 157.01, 155.52, 151.75, 139.68, 132.15, 130.09, 129.79, 129.18,128.67, 128.47, 128.38, 128.37, 128.20, 128.18, 128.16, 128.12, 127.99,127.69, 127.12, 125.99, 115.72, 115.52, 112.42, 112.04, 34.46, 25.76,25.75, 25.73, 25.64, 22.90, 20.67, 18.03, 14.39, 12.75.

(4,7,10,13,16,19Z)-3-hydroxy-5-((E)-4-hydroxystyryl)phenyl docosa-4,7,10,13,16,19-hexaenoate (29)

Deprotection of the protected DHA-resveratrol 28 (330 mg, 0.47 mmol) wasperformed with the general procedure and afforded 29 (191 mg, 75%) as awhite solid after 4h30 of reaction and purification on silica gelchromatography (Cyclohexane/AcOEt 80/20).

R_(f) (Hexane/AcOEt 70/30) 0.33; ¹H NMR (500 MHz, CDCl₃) δ 7.34 (d,J=8.6, 2H), 6.95 (d, J=16.3, 1H), 6.83-6.73 (m, 5H), 6.46 (t, J=2.1,1H), 5.55-5.25 (m, 12H), 5.12 (d, J=21.8, 2H), 2.95-2.74 (m, 10H),2.60-2.66 (m, 2H), 2.59-2.49 (m, 2H), 2.11-2.03 (m, 2H), 1.64 (s, 2H),0.97 (t, J=7.5, 3H); ¹³C NMR (126 MHz, CDCl₃) δ 172.03, 156.61, 155.65,151.87, 140.32, 132.22, 129.95, 129.92, 129.68, 128.73, 128.54, 128.44,128.43, 128.26, 128.23, 128.23, 128.12, 128.03, 127.59, 127.16, 125.50,34.49, 25.80, 25.78, 25.76, 25.68, 22.94, 20.71, 14.43.

Example 4: Synthesis of1-phloroglucinol-2-DHA-glycerophosphatidyl-choline Conjugate

DHA could accumulate in retina and brain through specific uptake ofDHA-containing lysophosphatidylcholine (1-Lyso-2-DHA-PC or LysoPCDHA21). Since DHA at the sn-2 position of LysoPCDHA, is considered as thephysiological form of this polyunsaturated LysoPC, the coupling reactionof the phenolic moiety was performed at the sn-1 position. A method wasdeveloped, based on the sn1-LysoPCDHA 21, perfect intermediate to accessthe desired lipophenol from a chemical coupling with a phloroglucinolbearing an acidic linker. To quantitatively obtain compound 21, theenzymatic hydrolysis was performed in EtOH/H₂O 95/5. Using 200% (w/w) ofenzyme and a reaction time of 40 h, the reaction led to 50% of purifiedLysoPC-DHA 21. Adding another portion of enzyme after 9 h and reducingthe overall reaction time to 29 h, we increased the yield of LysoPC-DHAup to 85%. It appears that longer reaction time facilitates migration ofDHA to the sn-1 position, to to form 1-DHA-2-LysoPC which, in turn,becomes the substrate of lipozyme for the regeneration ofglycerophosphocholine. HPLC monitoring of the crude material revealedthat in those conditions a very small proportion of migration wasobserved after 29 h of reaction. Moreover, according to HMBC NMRanalysis of isolated 21, the DHA at the sn-2 position was confirmed bythe presence of a coupling between the carbon of the carboxyl functionof DHA and the CH proton of the glycerol moiety.

A short linker was selected to link both lipidic and phenolic parts inorder to keep hydrophilic properties at the sn-1 position, to limitlipophilicity and to mimic as much as possible the physiological vectorLysoPCDHA. A glutaryl linker was introduced on the phloroglucinolbackbone using glutaric anhydride in the presence of DMAP (23). Then,the coupling step afforded the phospholipid conjugate 24 (65%) which wassubjected to the deprotection of the TIPS group and led to the desired1-glutaryl-phloroglucinol-2-DHA-PC 25 with an overall yield of 20% on 6steps starting from commercially available compounds.

1-lyso-2-docosahexaenoyl-sn-glycero-3-phosphatidylcholine 21: Thecommercially available (Coger, France) PC-16:0-DHA (25 mg, 0.03 mmol)was dissolved in ethanol 96% (250 μL) of in presence of the supportedlipozyme (immobilized from Mucor miehei) (25 mg). The mixture wasstirred at room temperature during 9 h and an additional amount ofsupported enzyme (25 mg) was added to the mixture. After 29 h of overallreaction, the supported enzyme was filtered off and washed with absoluteEtOH (3×3 mL) and chloroforme (3×3 mL). The filtrate was concentratedunder vacuum and purified on Sepak SiOH cartridge (CHCl₃/MeOH 100/0 to60/40) to give the sn1-Lyso-PC-DHA 21 (15 mg, 85%) as an uncoloured oil.15% of starting material (4 mg) was recovered after the purification.

R_(f) (CHCl₃/MeOH/H₂O 65/25/4) 0.19; ¹H NMR (500 MHz; CDCl₃) δ_(H)5.41-5.29 (m, 12H, CH═CH), 4.96-4.91 (m, 1H, CH—O), 4.34-4.28 (m, 2H,CH₂—O), 4.06-4.00 (m, 1H, CH_(2(a))—O), 3.98-3.92 (m, 1H, CH_(2(b))—O),3.80-3.75 (m, 2H, CH₂—N), 3.69-3.65 (m, 2H, CH₂—O), 3.32 (s, 9H,(CH₃)₃—N⁺), 2.85-2.79 (m, 10H, CH₂ bis-allylic), 2.37-2.34 (m, 4H,CH₂—C═O and CH₂ allylic), 2.07 (quint, J=7.5 Hz, 2H, CH₂ allylic), 0.97(t, J=7.5 Hz, 3H, CH₃); ¹³C NMR (125 MHz; CDCl₃) δ_(c) 172.9, 132.2,129.5, 128.8, 128.6, 128.5, 128.5, 128.3, 128.3, 128.2, 128.1, 128.1,127.2, 73.7, 66.4, 63.3, 60.0, 59.6, 54.5, 34.3, 25.8, 25.8, 25.8, 25.8,25.8, 22.8, 20.8, 14.5; HRMS (ESI-TOF) m/z: [M+H]⁺ calcd. for C₃₀H₅₁NO₇P568.3403; found 568.3409; HPLC rt: 25.80 min, (Atlantis C18 5 μm(4.6×250 mm), A: MeOH/H₂O/ACN 90/35/2.5, B: MeOH/H₂O/ACN 100/4/2.5,t_(0′=100/0), t_(15′=100/0), t_(30′=0/100), t_(50′0/100) , detection 205nm).

5-(3,5-bis(triisopropylsilyloxy)phenoxy)-5-oxopentanoic acid 23: Thedi-protected phloroglucinol 2 (100 mg, 0.23 mmol) was dissolved inCH₂Cl₂ (5 mL) in presence of pyridine (27 μL, 0.23 mmol). Glutaricanhydride (39 mg, 0.34 mmol) and DMAP (3 mg, 0.02 mmol) were added tothe solution at room temperature and the reaction was heated at 40° C.Additional equivalent of reagents (1.5 equiv. for glutaric anhydride and0.1 equiv. for DMAP) were added after one day of stirring. The reactionwas stopped after 4 days by addition of water (10 mL). The organic phasewas washed with water and brine, dried (MgSO₄) and concentrated undervacuum. The residue obtained was purified by chromatography on silicagel (pentane/AcOEt 90/10) to give the di-protected glutaratephloroglucinol 23 (90 mg, 71%) as a uncolored oil.

R_(f) (pentane/AcOEt 60/40) 0.50; RMN ¹H, CDCl₃, 500 MHz; δ ppm: 6.28(t, J=2.2 Hz, 1H, CH_(aro)), 6.25 (d, J=2.2 Hz, 2H, CH_(aro)), 2.61 (t,J=7.4 Hz, 2H, CH2_(glut)), 2.51 (t, J=7.3 Hz, 2H, CH_(2glut)), 2.06(quint, J=7.3 Hz, 2H, CH_(2glut)), 1.27-1.20 (m, 6H, CH—Si), 1.08 (d,J=7.3 Hz, 36H, (CH₃)₂C); ¹³C NMR (125 MHz; CDCl₃) δ_(c) 178.2, 170.8,157.1, 151.6, 109.3, 106.7, 33.2, 32.7, 19.7, 17.8, 12.6; HRMS (ESI-TOF)m/z: [M−H]⁻ calcd. for C₂₉H₅₁O₆Si₂ 551.3224; found 551.3214.

1-[5-(3,5-bis(triisopropylsilyloxy)phenoxy)-5-oxopentanoyl]-2-docosahexaenoyl-sn-glycero-3-phosphatidylcholine24: LysoPC-DHA 21 (15 mg, 0.02 mmol) and the di-protected glutaricphloroglucinol 23 (16 mg, 0.02 mmol) were dissolved in dry CH₂Cl₂ (2mL). DCC (6 mg, 0.03 mmol) and DMAP (1 mg, 8.30 μmol) were added to thesolution and the reaction was stirred at room temperature for 24 h undernitrogen. The solvent was evaporated under reduced pressure and theresidue obtained was purified on Sepak SiOH cartridge (CHCl₃/MeOH 100/0to 60/40) to give the desired polyphenolic-PC-DHA 24 (19 mg, 65%) as anuncoloured oil. 33% of starting material (5 mg) were recovered duringthe purification.

R_(f) (CHCl₃/MeOH/H₂O 65/25/4) 0.40; ¹H NMR (500 MHz; CDCl₃) δ_(H) 6.28(t, J=2.5 Hz, 1H, CH_(aro)), 6.23 (t, J=2.5 Hz, 2H, CH_(aro)), 5.41-5.28(m, 12H, CH═CH), 5.25-5.20 (m, 1H, CH—O), 4.43 (dd, J=3.0 Hz, J=12.0 Hz,1H, CH_(2(a))—O), 4.36-4.30 (m, 2H, CH₂—O), 4.17 (dd, J=6.5 Hz, J=12.0Hz, 1H, CH_(2(b))—O), 4.02-3.95 (m, 2H, CH₂—O), 3.80-3.77 (m, 2H,CH₂—N), 3.35 (s, 9H, (CH₃)₃—N⁺), 2.84-2.79 (m, 10H, CH₂ bis-allylic),2.57 (t, J=7.5 Hz, 2H, CH₂—C═O_((glut))), 2.43 (t, J=7.5 Hz, 2H,CH₂—C═O_((glut))), 2.39-2.35 (m, 4H, CH₂—C═O_((DHA)) and CH₂ allylic),2.07 (quint, J=7.5 Hz, 2H, CH₂ allylic), 2.00 (quint, J=7.5 Hz, 2H,CH_(2(glut))), 1.24-1.18 (m, 6H, CH—Si), 1.08 (d, J=7.5 Hz, 36H,(CH₃)₂C), 0.97 (t, J=7.5 Hz, 3H, CH₃); ¹³C NMR (125 MHz; CDCl₃) δ_(c)172.8, 172.7, 171.2, 157.4, 151.9, 132.2, 129.5, 128.7, 128.5, 128.5,128.5, 128.3, 128.3, 128.2, 128.1, 128.0, 127.2, 109.5, 107.0, 70.8,66.8, 63.4, 63.3, 59.4, 54.9, 34.3, 33.5, 33.2, 25.8, 25.8, 25.7, 22.8,20.8, 20.1, 18.1, 14.5, 12.8; HRMS (ESI-TOF) m/z: [M+H]⁺ calcd. forC₅₉H₁₀₁NO₁₂PSi₂ 1102.6594; found 1102.6608.

1-[5-(3,5-dihydroxyphenoxy)-5-oxopentanoyl]-2-docosahexaenoyl-sn-glycero-3-phosphatidylcholine 25: To a solution of 24 (17 mg, 0.01mmol) in dry THF (0.50 mL), was added Et₃N-3HF (10 μL, 0.06 mmol). Thereaction was stirred at room temperature during 4 h. The solvent wasevaporated under reduced pressure and the residue obtained was purifiedon Sepak SiOH cartridge (CHCl₃/MeOH 100/0 to 80/20) to give the desireddeprotected polyphenolic-PC-DHA 25 (10.20 mg, 84%) as an uncoloured oil.

R_(f) (CHCl₃/MeOH/H₂O 65/25/4) 0.30; ¹H NMR (500 MHz; CDCl₃) δ_(H) 6.43(s, 1H, CH_(aro)), 6.10 (s, 2H, CH_(aro)), 5.42-5.28 (m, 12H, CH═CH),5.18-5.14 (m, 1H, CH—O), 4.42-4.37 (m, 1H, CH_(2(a))—O), 4.21-4.13 (m,3H, CH_(2(b))—O and CH₂—O), 4.04-3.98 (m, 2H, CH₂—O), 3.52-3.46 (m, 2H,CH₂—N), 3.03 (s, 9H, (CH₃)₃—N⁺), 2.84-2.81 (m, 10H, CH₂ bis-allylic),2.56-2.51 (m, 2H, CH₂—C═O_((glut))), 2.46-2.41 (m, 2H,CH₂—C═O_((glut))), 2.37-2.33 (m, 4H, CH₂—C═O_((DHA)) and CH₂ allylic),2.07 (quint, J=7.5 Hz, 2H, CH₂ allylic), 2.01-1.95 (m, 2H,CH_(2(glut))), 0.97 (t, J=7.5 Hz, 3H, CH₃); ¹³C NMR (125 MHz; CDCl₃)δ_(c) 172.7, 172.6, 172.1, 159.5, 152.5, 132.2, 129.5, 128.8, 128.5,128.5, 128.5, 128.3, 128.3, 128.3, 128.1, 128.0, 127.2, 101.4, 101.2,70.5, 66.1, 63.5, 62.3, 59.7, 54.0, 34.0, 33.1, 33.0, 25.9, 25.8, 25.8,25.8, 22.8, 20.8, 20.4, 14.5; HRMS (ESI-TOF) m/z: [M+H]⁺ calcd. forC₄₁H₆₁NO₁₂P 790.3931; found 790.3940; HPLC rt: 24.12 min, (Atlantis C185 μm (4.6×250 mm), A: MeOH/H₂O/ACN 90/35/2.5, B: MeOH/H₂O/ACN 100/4/2.5,t_(0′=100/0), t_(15′=100/0), t_(30′=0/100), t_(50′=0/100) , detection272 nm).

Example 5: Synthesis of EPA-Phloroglucinol Conjugate Preparation of(5,8,11,14,17 Z)-3,5-dihydroxyphenyl icosa-5,8,11,14,17-pentaenoate

Coupling of the di-TIPS-phloroglucinol 2 (652 mg, 1.48 mmol) and EPA(543 mg, 1.79 mmol) was performed according to the general procedureused in example 1 and afforded the protected phloroglucinol-EPA (753 mg,70%) as an uncolored oil after purification on silica gel chromatography(hexane/AcOEt 99.7/0.3).

Deprotection of this protected EPA-phloroglucinol (830 mg, 1.15 mmol)was performed using the general procedure used in example 1 and affordedthe (5,8,11,14,17 Z)-3,5-dihydroxyphenyl icosa-5,8,11,14,17-pentaenoate(455 mg, 96%) as an uncolored oil after purification on silica gelchromatography (hexane/AcOEt 9/1 to 7/3).

R_(f) (hexane/AcOEt 7/3) 0.3; ¹H NMR (500 MHz, CDCl₃) δ 6.09 (s, 3H),5.46-5.30 (m, 10H), 2.85-2.80 (m, 8H), 2.57 (t, J=7.5 Hz, 2H), 2.20 (q,J=7.0 Hz, 2H), 2.10-2.05 (m, 2H), 1.83 (q, J=7.5 Hz, 2H), 0.97 (t, J=7.5Hz, 3H); ¹³C NMR (126 MHz, CDCl₃) δ 173.8, 157.6, 152.0, 132.3, 129.5,128.8, 128.8, 128.5, 128.5, 128.3, 128.3, 128.1, 127.2, 102.1, 101.4,34.0, 26.7, 25.9, 25.8, 25.7, 24.8, 20.8, 14.5.

Example 6: Synthesis of Alkylated EPA-Phloroglucinol ConjugatePreparation of (5,8,11,14,17 Z)-3-hydroxy-5-isopropoxyphenylicosa-5,8,11,14,17-pentaenoate

Coupling of the mono-TIPS-mono-isopropyl-phloroglucinol 11b (70 mg, 0.22mmol) and EPA (65 mg, 0.22 mmol) was performed according to the generalprocedure used in example 1 and afforded the protectedmono-isopropyl-phloroglucinol-EPA (71 mg, 54%) as an uncolored oil afterpurification on silica gel chromatography (hexane/AcOEt 99.5/0.5).

Deprotection of this protected EPA-phloroglucinol (65 mg, 0.11 mmol) wasperformed using the general procedure used in example 1 and afforded(5,8,11,14,17 Z)-3-hydroxy-5-isopropoxyphenylicosa-5,8,11,14,17-pentaenoate (37 mg, 76%) as an uncolored oil afterpurification on silica gel chromatography (hexane/AcOEt 9/1).

R_(f) (hexane/AcOEt 9/1) 0.3; ¹H NMR (500 MHz, CDCl₃) δ 6.22 (t, J=2.2Hz, 1H), 6.18 (t, J=2.1 Hz, 1H), 6.14 (t, J=2.1 Hz, 1H), 5.64 (br, 1H),5.48-5.28 (m, 10H), 4.44 (quint, J=6.0 Hz, 1H), 2.83-2.80 (m, 8H), 2.56-2.53 (m, 2H), 2.21-2.17 (m, 2H), 2.12-2.02 (m, 2H), 1.82 (quint, J=7.5Hz, 2H), 1.30 (d, J=6.0 Hz, 6H), 0.97 (t, J=7.5 Hz, 3H); ¹³C NMR (126MHz, CDCl₃) δ 172.7, 159.8, 157.5, 152.3, 132.4, 129.4, 129.0, 128.9,128.6, 128.5, 128.5, 128.4, 128.2, 127.3, 101.9, 101.9, 101.3, 70.6,34.0, 26.8, 25.9, 25.9, 25.8, 25.8, 25.0, 22.2, 20.9, 14.6.

Example 7: Synthesis of Alkylated Docosanoic-Phloroglucinol ConjugatePreparation of 3-hydroxy-5-isopropoxyphenyl docosanoate

Docosanoic acid (136.6 mg, 0.40 mmol) and themono-TIPS-mono-isopropyl-phloroglucinol 11b (100 mg, 0.30 mmol) weredissolved in dry CH₂Cl₂(6 mL) and dry DMF (1.5 mL). DCC (82.7, 0.40mmol) and DMAP (5 mg, 0.04 mmol) were added to the solution and thereaction was stirred at room temperature for 5 h under nitrogen, andthen overnight at 50° C. Then, the mixture was left 2 h at 4° C. toinduce dicyclohexylurea crystallization. The urea residue was thenfiltered off, and the filtrate was washed with water and brine. Theorganic layer was dried on MgSO₄ and concentrated under reducedpressure. Purification of the crude material was performed bychromatography on silica gel (hexane/AcOEt 99.5/0.5) to afford (95 mg,48%) the protected derivative as an uncolored oil.

Deprotection of this protected-docosanoic-phloroglucinol (90 mg, 0.14mmol) was performed using the general procedure used in example 1 andafforded 3-hydroxy-5-isopropoxyphenyl docosanoate (56 mg, 82%) as whitesolid after purification on silica gel chromatography (hexane/AcOEt9/1).

R_(f) (hexane/AcOEt 9.5/0.5) 0.3; ¹H NMR (500 MHz, CDCl₃) δ 6.22 (t,J=2.2 Hz, 1H), 6.17 (t, J=2.1 Hz, 1H), 6.14 (t, J=2.1 Hz, 1H), 6.07 (br,1H), 4.44 (hept, J=6.1 Hz, 1H), 2.52 (t, J=7.6 Hz, 2H), 1.75-1.69 (m,2H), 1.42-1.34 (m, 4H), 1.30 (d, J=6.1 Hz, 6H), 1.28-1.22 (m, 30H), 0.88(t, J=7.0 Hz, 3H); ¹³C NMR (126 MHz, CDCl₃) δ 173.1, 159.8, 157.7,152.4, 102.0, 101.9, 101.26, 70.6, 34.8, 32.3, 30.0, 30.0, 29.7, 29.8,29.7, 29.6, 29.4, 25.2, 23.0, 22.3, 14.5.

Example 8: Preparation of (9,12,15Z)-3-hydroxy-5-isopropoxyphenyloctadeca-9,12,15-trienoate (PG-OiP-ALA)(9,12,15Z)-3-isopropoxy-5-((triisopropylsilyl)oxy)phenyloctadeca-9,12,15-trienoate (34)

Coupling of the mono-TIPS-mono-isopropyl-phloroglucinol 11b (70 mg, 0.22mmol) and ALA (60 mg, 0.22 mmol) was performed according to the generalprocedure used in example 1 and afforded the protectedmono-isopropyl-phloroglucinol-ALA 34 (101 mg, 80%) as an uncolored oilafter purification on silica gel chromatography (hexane/AcOEt 99.5/0.5).

R_(f) (hexane/AcOEt 99/1) 0.2; ¹H NMR (500 MHz, CDCl₃) δ 6.28 (t, J=2.1Hz, 1H), 6.23 (t, J=2.1 Hz, 1H), 6.20 (t, J=2.1 Hz, 1H), 5.42-5.29 (m,6H), 4.44 (sept, J=6.0 Hz, 1H), 2.82-2.80 (m, 4H), 2.50 (t, J=7.5 Hz,2H), 2.11-2.04 (m, 4H), 1.72 (quint, J=7.5 Hz, 2H), 1.43-1.34 (m, 8H),1.30 (d, J=6.0 Hz, 6H),1.27-1.19 (m, 3H), 1.09 (d, J=7.3 Hz, 18H), 0.97(t, J=7.5 Hz, 3H); ¹³C NMR (126 MHz, CDCl₃) δ 172.3, 159.5, 157.7,152.3, 132.3, 130.6, 128.6, 128.6, 128.1, 127.4, 106.4, 105.6, 102.7,70.5, 34.8, 29.9, 29.5, 29.5, 29.4, 27.5, 25.9, 25.9, 25.2, 22.3, 20.9,18.2, 14.6, 12.9.

(9,12,15Z)-3-hydroxy-5-isopropoxyphenyl octadeca-9,12,15-trienoate (35)

Deprotection of the protected ALA-phloroglucinol 34 (90 mg, 0.15 mmol)was performed using the general procedure used in example 1 and affordedcoumpound 35 PG-OiP-ALA (56 mg, 58%) as an uncolored oil afterpurification on silica gel chromatography (hexane/AcOEt 9/1).

R_(f) (hexane/AcOEt 8/2) 0.5; ¹H NMR (500 MHz, CDCl₃) δ 6.22 (t, J=2.1Hz, 1H), 6.17 (t, J=2.1 Hz, 1H), 6.13 (t, J=2.1 Hz, 1H), 5.87 (Br, 1H),5.42-5.29 (m, 6H), 4.44 (sept, J=6.0 Hz, 1H), 2.82-2.80 (m, 4H), 2.52(t, J=7.5 Hz, 2H), 2.11-2.04 (m, 4H), 1.73 (quint, J=7.5 Hz, 2H),1.43-1.32 (m, 8H), 1.30 (d, J=6.0 Hz, 6H), 0.97 (t, J=7.5 Hz, 3H); ¹³CNMR (126 MHz, CDCl₃) δ 173.1, 159.8, 157.6, 152.3, 132.3, 130.6, 128.6,128.6, 128.1, 127.4, 102.0, 101.9, 101.3, 70.6, 34.8, 29.9, 29.5, 29.4,29.4, 27.5, 25.9, 25.8, 25.2, 22.2, 20.9, 14.6.

Example 9: Synthesis of Deuterated Fatty Acid-Alkyl-Phloroglucinol

11,11,14,14-D₄-(9,12,15Z)-3-isopropoxy-5-((triisopropylsilyl)oxy)phenyloctadeca-9,12,15-trienoate (30)

Coupling of the mono-TIPS-mono-isopropyl-phloroglucinol 11b (104 mg,0.32 mmol) and ALA(D₄) (100 mg, 0.35 mmol) (ALA(D₄) was furnished byRetrotope company) was performed with the general procedure as explainedin example 1 and afforded 30 (133 mg, 71%) as an uncolored oil afterpurification on silicagel chromatography (Cyclohexane/AcOEt 99/1).

R_(f) (Hexane/AcOEt 95/5) 0.6; ¹H NMR (500 MHz, CDCl₃) δ 6.28 (t, J=2.2Hz, 1H), 6.23 (t, J=2.1 Hz, 1H), 6.20 (t, J=2.1 Hz, 1H), 5.46-5.26 (m,6H), 4.44 (hept, J=6.0 Hz, 1H), 2.51 (t, J=7.5 Hz, 2H), 2.15-1.99 (m,4H), 1.80-1.65 (m, 2H), 1.45-1.32 (m, 8H), 1.31 (d, J=6.1 Hz, 6H),1.29-1.19 (m, 3H), 1.10 (d, J=5.0 Hz, 19H), 0.98 (t, J=7.5 Hz, 3H); ¹³CNMR (126 MHz, CDCl₃) δ 132.10, 130.38, 128.30, 127.76, 127.12, 106.14,105.41, 102.47, 22.09, 18.00, 14.40, 12.71.

11,11,14,14-D₄-(9,12,15Z)-3-hydroxy-5-isopropoxyphenyloctadeca-9,12,15-trienoate (31)

Deprotection of the protected ALA(D₄)-mono-isopropyl-phloroglucinol 30(120 mg, 0.20 mmol) was performed through the general procedure asexplained in exsample 1 and afforded 31 (67 mg, 77%) as an uncolouredoil after purification on silica gel chromatography (Cyclohexane/AcOEt95/5).

R_(f) (Hexane/AcOEt 90/10) 0.19; ¹H NMR (500 MHz, CDCl₃) δ 6.22 (t,J=2.2, 1H), 6.17 (t, J=2.1, 1H), 6.13 (t, J=2.1, 1H), 5.97 (s, 1H),5.45-5.28 (m, 6H), 4.44 (hept, J=6.1, 1H), 2.53 (t, J=7.6, 2H),2.18-1.97 (m, 4H), 1.81-1.65 (m, 2H), 1.44-1.32 (m, 8H), 1.30 (d, J=6.1,6H), 0.98 (t, J=7.5, 3H); ¹³C NMR (126 MHz, CDCl₃) δ 172.94, 159.60,157.44, 152.13, 132.10, 130.37, 128.33, 128.28, 127.78, 127.12, 101.77,101.74, 101.10, 70.41, 34.55, 29.69, 29.26, 29.21, 29.16, 27.31, 24.99,22.04, 20.67, 14.41.

11,11-D₂-(9,12Z)-3-isopropoxy-5-((triisopropylsilyl)oxy)phenyloctadeca-9,12-dienoate (32)

Coupling of the mono-TIPS-mono-isopropyl-phloroglucinol 11b (104 mg,0.32 mmol) and LA(D₂) (100 mg, 0.35 mmol) (LA(D₂) was furnished byRetrotope company) was performed with the general procedure of example 1and afforded 32 (153 mg, 81%) as an uncolored oil after purification onsilica gel chromatography (Cyclohexane/AcOEt 99/1).

R_(f) (Hexane/AcOEt 95/5) 0.75; ¹H NMR (500 MHz, CDCl₃) δ 6.28 (t, J=2.2Hz, 1H), 6.23 (t, J=2.1 Hz, 1H), 6.20 (t, J=2.1 Hz, 1H), 5.45-5.27 (m,4H), 4.44 (hept, J=6.1 Hz, 1H), 2.51 (t, J=7.5 Hz, 2H), 2.12-1.99 (m,4H), 1.74-1.71 (m, 2H), 1.46-1.17 (m, 23H), 1.09 (d, J=7.2 Hz, 18H),0.89 (t, J=7.0 Hz, 3H); ¹³C NMR (126 MHz, CDCl₃) δ 172.05, 159.23,157.47, 152.12, 130.37, 130.17, 128.07, 127.90, 106.14, 105.41, 102.47,70.26, 34.54, 31.64, 29.72, 29.47, 29.29, 29.23, 29.19, 27.32, 27.31,25.02, 22.69, 22.09, 18.00, 17.99, 14.19, 12.72, 12.71.

11,11-D₂-(9Z,12Z)-3-hydroxy-5-isopropoxyphenyl octadeca-9,12-dienoate(33)

Deprotection of the protected LA(D₂)-mono-isopropyl-phloroglucinol 32(130 mg, 0.22 mmol) was performed through the general procedure asexplained in example 1 and afforded 33 (84 mg, 88%) as an uncoloured oilafter purification on silica gel chromatography (Cyclohexane/AcOEt95/5).

R_(f) (Hexane/AcOEt 90/10) 0.23; ¹H NMR (500 MHz, CDCl₃) δ 6.22 (t,J=2.2, 1H), 6.17 (t, J=2.1, 1H), 6.13 (t, J=2.1, 1H), 5.89 (s, 1H),5.46-5.28 (m, 4H), 4.44 (hept, J=6.1, 1H), 2.56-2.49 (m, 2H), 2.11-1.99(m, 4H), 1.73 (m, 2H), 1.47-1.32 (m, 10H), 1.30 (d, J=10.0, 6H), 0.89(t, J=7.0, 3H); ¹³C NMR (126 MHz, CDCl₃) δ 172.93, 159.62, 157.43,152.15, 130.39, 130.17, 128.09, 127.91, 101.78, 101.76, 101.10, 70.41,34.56, 31.64, 29.72, 29.47, 29.27, 29.22, 29.17, 27.33, 27.31, 25.01,22.70, 22.05, 14.20.

Example 10: Effect of Lipophenol on All-Trans-Retinal Toxicity inARPE-19 Cell Line

In order to evaluate the ability of lipophenols to protect cells againstall-trans-retinal toxicity, the synthesized derivatives were incubatedin retinal pigment epithelium (ARPE-19 cell lines) cell cultures. Thebiological assay is based on the measure of cell survival aftertreatment with the lipophenol prior incubation (pre-incubation process)with the carbonyl stressor AtR. The toxic AtR concentration (25 μM) wasdetermined to reduce cell survival by 60 to 70%. The effect oflipophenols on cell viability at 10 μM and 40 μM are presented in table1 and FIG. 12. Results are expressed as % of cell survival in treated(lipophenol/all-trans-retinal) vs untreated cells (taken as 100%).

ARPE-19 cells were obtained from ATCC and grown following theinstructions in Dulbecco's Modified Eagle's Medium (DMEM)/Ham'F12(GIBCO) containing 10% (v/v) Foetal Bovine Serum, 1% (v/v) antibioticsat 95% air/5% CO₂ atmosphere at 37° C. ARPE-19 cells were settled in96-well plates (3×10⁴ cells/well) and cultured 24 h to reach confluencebefore drug treatment. Cell cultures received a serum-free mediumcontaining drugs at different concentrations (10-40 μM) for one hour andtrans-retinal (25 μM) was added for 4 more hours before rinsing withmedium. The viability of cells in triplicate samples was determined16-20 h after with a MTT colorimetric assay. After 2 h incubation with0.5 mg/ml MU, insoluble purple formazan produced was dissolved in DMSO.The absorbance at 570 nm and 655 nm of individual wells was measured bya microplate reader (BioRad 550). The percentage of viable cells wascalculated as [(OD570 sample-OD655 sample)/(OD570 control−OD655control)]×100, controls corresponding of cells incubated with 0.2% DMSOand 0.14% DMF.

Table 1 hereafter shows the results of ARPE-19 cell viability in thepresence of lipophenol and AtR.

% Survival n Untreated cell 100 AtR (25 μM) 29.1 ± 5.4 7 ^([a]) % ^([a])% Survival Survival Compounds 10 μM 40 μM n Phloroglucinol 35.5 ± 3.341.6 ± 9.2 3 Compound 8 33.3 ± 4.1 47.7 ± 3.2 3 Compound 13a 32.6 ± 3.744.9 ± 1.9 3 Compound 13b 43.2 ± 7.5 66.8 ± 8.6 4 Compound 9b 30.6 ± 1.232.7 ± 1.8 3 DHA 23.5 ± 2.7  7.3 ± 5.0 3 DHA + 9b 29.0 ± 1.7  10 ± 2.6 3^([a]) Incubation of lipophenols 1 h followed by AtR incubation at 25 μMduring 4 h. Cell viability is measured by MTT assay after 16-20 h. Eachexperiment have been performed in triplicate

The biological evaluation showed the phloroglucinol to be moderately toweakly active with an increase of RPE cell survival of 10% at 40 μM.

Increasing DHA parts, leads to active derivatives able to reach 50% ofcell survival as observed for 8 (PG-TriDHA). Mono DHA-alkylatedlipophenol 13a revealed to be as active as 8. The highest increase ofviability (70%) was observed for 13b (mono-isopropyl derivative) in adose-dependent manner (FIG. 1).

To confirm the interest in the conception of the lipophenol conjugate13b, a mixture of DHA and mono-isopropyl phloroglucinol 9b was evaluated(in the same conditions) and presented an important toxicity, comparableto what is observed by treatment with DHA alone. This result stronglysupports that introduction of a PUFA moiety on theO-alkylated-polyphenol backbone, is a promising approach to obtainpotent derivatives.

Example 11: Biological Assessment of the Protective Effects ofPhloroglucinol-Isopropyl-DHA (Compound 13b) AgainstAll-Trans-Retinal-Induced Carbonyl and Oxidative Stresses in the Retina

Following light stimulation, the visual chromophore 11-cis-retinal,which is covalently linked to photoreceptor opsins to form the visualpigments (rhodopsin), is photoisomerase to all-trans-retinal (atRal).This latter triggers the phototransduction through activation of theopsin before being released in the photoreceptor outer segment (POS)disc membranes. An excess of free all-trans-retinal following high levelexposal to light is very reactive with amines and may cause both acutecarbonyl and oxidative stresses. This accumulation of retinal worsenswhen loss-of-function mutations in the ABCA4 and/or RDH8/12 genes, whichencode protein partners releasing retinal from the membrane and reducingit to retinol, are present in patients with retinopathies. The retinalpigment epithelium (RPE), whose apical microvilli are juxtaposed to thePOS, contributes to the renewal of POS by daily phagocytosis. The latterwill lead to lipofuscin accumulation and its excessive levels eventuallycause RPE death as part of the pathophysiological process in severalsight-threatening diseases such as Stargardt disease and age-relatedmacular degeneration. The bisretinoid derivatives (RALdi, A2E) formationin the lipofuscin can contribute to generation of non-degradablematerial and be toxic to RPE again through oxidative and carbonylstress.

Cytoprotective Action of Compound 13b in Neural Retina Cell Cultures

The effect of compound 13b on cell viability was examined afterco-incubation with atRal. Cell cultures were incubated with 13b (10 to100 μM) and atRal (50-75-100 μM) was added 1 h after for a 4 hco-incubation. Cells were then cultured in serum-free medium for 16-20 hand their viability was determined with a MTT assay. It was found thatall atRal concentrations caused cytotoxicity that was robustly reversedby 13b treatment in a dose-dependent manner (FIG. 2). Therefore, it wasdemonstrated that the cytotoxicity of atRal on neural retina could beefficiently neutralized by an alkylated-phloroglucinol-DHA conjugate.

Mitochondrial Respiration

Oxidative stress originates from physiological reactions taking placepractically inside each cell of an organism. The production of reactiveoxygen species (ROS) accompanies, for example, oxidativephosphorylation-derived ATP-based energy metabolism which takes place inthe mitochondria of a cell. Under physiological conditions, ROS areneutralized by effective enzymatic and non-enzymatic defense mechanisms,contributing to the maintenance of a proper balance. However, an excessof ROS, resulting from their overproduction in pathophysiologicalconditions, will disturb the equilibrium and lead eventually todeleterious consequences for the cell. Maeda et al. (JBC 284(22), 2009)have reported that atRal impairs mitochondrial oxidativephosphorylation. Therefore, mitochondrial respiration was measured inARPE-19 cell line using oxygraph after exposure to 25 μM atRal and/or 40μM 13b (FIG. 3). AtRal strongly inhibits the activity of complexes CIand CII while 13b partially reverse this inhibition, 13b showing nosignificant inhibition of the activity of each complex.

Such results confirmed the mitochondrial poisoning by atRal and therescue by phloroglucinol-isopropyl-DHA.

Example 12: Protective Activity of Lipophenol Conjugates against atRALin RPE Cells (ARPE-19 Cell Line and RPE Primary Cultures) ProtectiveEffects of Lipophenols on ARPE-19 Cell Lines in the Presence of atRAL(25 μM)

Further to the results of examples 10 and 11, the lipophenols of theinvention were incubated in retinal pigment epithelium (ARPE-19 celllines) cell cultures and the biological assay is based on the measure ofcell survival after treatment with the lipophenol prior incubation for 4hours with the carbonyl stressor AtR at 25 μM (co-treatment process).

Co-treatment were performed with lipophenols onto ARPE-19 (FIG. 4).Incubation for 4 h with atRAL decreased cell viability to 35%. Theprotection of ARPE-19 by phloroglucinol (PG) was dose-dependent but weak(less than 10%). In contrast, most of the PG derivatives were moreprotective, in particular the presence of two or three DHA linked to PGprovided a strong protection (up to 73% survival), as well as themono-alkylation (methyl and isopropyl) were sufficient to protect 60% ofcells. PG-OiP-DHA was confirmed to be among the most efficient (74%).Interestingly, resveratrol-DHA was also very potent, whereas DHAappeared to be toxic.

Mitochondrial Enzymatic Activities and Protein Expression

In a cellular context, PG-OiP-DHA (compound 13b) has been shown able topartially restore mitochondrial oxidative respiration impaired by theatRAL (example 10). Because this repair might be produced by targetingthe whole oxidative chain or each individual respiratory complex, thispotency was further investigated by measuring the intrinsic activity ofeach mitochondrial respiratory chain (MRC) complex (enzymology) andtheir level of protein expression (FIG. 5). The enzymatic activitiesindicated that complex II and IV were affected by atRAL andsignificantly preserved by PG-OiP-DHA. Citrate synthase (CS) activitymarkedly dropped with atRAL treatment, suggesting a loss ofmitochondrial mass related to necrotic cell death. This was supported bythe loss of MRC protein expression. Altogether, PG-OiP-DHA showed aprotective effect on the mitochondrial activity.

Characterization of atRAL-Induced Cell Death

Further investigations were made to define the atRAL-induced cell death(apoptotic versus necrotic) and validate the protective effect ofPG-OiP-DHA (FIG. 6). Cells were incubated for 4 h with atRAL 25 μM,PG-OiP-DHA (compound 13b) 40 μM, or both. Treated ARPE-19 were labeledwith Annexin V-FITC (A) and propidium iodide (PI) to separate by flowcytometry healthy cells (no labeling), early apoptosis (A+ and PI−) andnecrotic cells (A+ and PI+). In CTL or PG-OiP-DHA-treated cells only 6to 10% died. After 4 h atRAL, cell death reached 46%, mainly at necroticstage (41%). Co-incubation with PG-OiP-DHA markedly reduced both thetotal cell death (18%) and the necrotic cells (16%).

Primary RPE Cultures

a. Pre-treatment 24 h, H₂O₂ 450 μM 2 h; cell viability assay

To compare the anti-oxidant efficacies of phloroglucinol (10% gain ofsurvival) and PG-OiP-DHA (20%) in the RPE (FIG. 7). These resultssuggest that both contributed by pre-treatment to reduce theH₂O₂-induced oxidative damage, and PG-OiP-DHA appears to be moreprotective in primary RPE cells.

b. Pre-treatment 24 h, atRAL 25 μM 4 h; cell viability assay

To compare the anti-carbonyl efficacies of phloroglucinol (18% gain ofsurvival) and PG-OiP-DHA (42%) in the RPE (FIG. 8). These resultssuggest that both contributed by pre-treatment to reduce theatRAL-induced cell damage, and PG-OiP-DHA appears to be more protectiveat higher concentrations, in primary RPE cells.

c. Co-incubation 4 h with atRAL 25 μM; cell viability assay

To compare the anti-carbonyl efficacies of phloroglucinol (22% gain ofsurvival) and PG-OiP-DHA (69%) in a condition to probe their scavengingproperties in primary RPE cells (FIG. 9). These results show that bothcontributed by co-treatment to reduce the atRAL-induced cell damage, andPG-OiP-DHA appears to be more protective at lower concentrations.

Example 13: Effect of the Polyunsaturated Fatty Acid (PUFA) andIsopropyl Alkylation for the Protection Effect of the Presence of a PUFAResidue

Some experiments (in ARPE-19 cell lines) were made to compare theanti-carbonyl efficacies of PG-OiP-ALA (C18:3 ω-3)(compound 35),PG-OiP-EPA (C20:5 ω-3)(compound of example 6), PG-OP-DHA (C22:6ω-3)(compound 13b), and saturated C22 (compound of example 7) (FIGS. 10and 11).

The rank of efficacy was DHA>EPA=ALA>C22, demonstrating that thepresence of PUFA was most advantageous for the activity. However therewas no correlation between the efficacy and the number or the positionof double bounds.

Effect of the Presence of an Alkyl Group

Several experiments (in ARPE-19 cell lines) were made to study theeffect of the presence of an alkyl group, in particular of an isopropylgroup.

These experiments compare the anti-carbonyl efficacies of PG-EPA andPG-DHA (without alkyl part) and the corresponding PG-OiP-EPA andPG-OiP-DHA (FIG. 13). Whatever the PUFA, isopropyl was necessary for theproper protection.

Mitochondrial Enzymatic Activities and MRC Protein Expression

Several experiments were made to validate the efficacy of PG-OiP-DHA inthe protection of the mitochondrial activity (FIG. 14). The enzymaticactivities indicated that complex II and IV were affected by atRAL andsignificantly preserved by PG-OP-DHA. These results were supported bythe analysis of MRC protein expression (FIG. 15).

The invention claimed is:
 1. A method for treating a retinal pathologycaused by either or both carbonyl and oxidative stress, comprising astep of administering to a patient in need thereof a pharmaceuticallyacceptable amount of a compound of formula (I):

wherein: i is 0 or 1; j is 0 or 1; k is 0 or 1; R₁ is chosen from thegroup consisting of: H, (C₁-C₁₂)alkyl, (C₃-C₆)cycloalkyl, and(C₆-C₁₀)aryl radicals; or R₁ may form a heterocycloalkyl radical withthe oxygen atom bearing it; or R₁ is a group of formula C(O)R, R beingas defined below; R₂ is chosen from the group consisting of: H,(C₁-C₁₂)alkyl, (C₃-C₆)cycloalkyl, and (C₆-C₁₀)aryl radicals; or R₂ mayform a heterocycloalkyl radical with the oxygen atom bearing it; or R₂is a group of formula C(O)R, R being as defined below; R is a, linear orbranched, alkyl radical, possibly interrupted by one or several doublebonds, comprising at least 19 carbon atoms, and wherein one or severalhydrogen atoms may be replaced by deuterium atoms; R₃ is H and k=0 whenj=1; or, when j=0, R₃ is a group of formula —C(O)R or -L-C(O)R, R beingas defined above; L is a linker having one of the following formulae(L1) or (L2):

wherein: A₁ is an alkylene radical comprising from 3 to 6 carbon atoms;A′₁ is an alkylene radical comprising from 1 to 6 carbon atoms,optionally interrupted by one or several heteroatoms, such as oxygenatoms; X₁ is a radical —C(O)— or an alkylene radical comprising from 1to 6 carbon atoms; X₂ is a radical —C(O)— or an alkylene radicalcomprising from 1 to 6 carbon atoms; X′₁ is chosen from the groupconsisting of: —O—, —N(R_(a))— or an alkylene radical comprising from 1to 6 carbon atoms, optionally interrupted by one or several heteroatoms,such as oxygen atoms, R_(a) being H or an alkyl group comprising from 1to 6 carbon atoms; L′ is a linker of formula -(A)_(p)-(X)_(q)—C(O)—,wherein: p is 0 or 1; q is 0 or 1; A is an alkylene radical comprisingfrom 1 to 6 carbon atoms, optionally interrupted by one or severalheteroatoms, such as oxygen atoms, X is —O—, —N(R_(b))— or an alkyleneradical comprising from 1 to 6 carbon atoms, R_(b) being H or an alkylgroup comprising from 1 to 6 carbon atoms; L″ is a linker chosen fromthe group consisting of: (C₆-C₁₀)arylene, (C₁-C₁₂)alkylene,(C₁-C₁₂)alkylene-(C₆-C₁₀)arylene, (C₆-C₁₀)arylene-(C₁-C₁₂)alkylene,—CH═CH-(C₆-C₁₀)arylene and (C₁-C₁₂)alkylene-CH═CH-(C₆-C₁₀)aryleneradicals; wherein, when j=0, at least one of the groups R₁, R₂ and R₃comprises a radical R; provided that the compound of formula (I) isother than the following compound:

or its pharmaceutically acceptable salts, racemates, diastereomers orenantiomers.
 2. The method of claim 1, wherein, in formula (I), whenj=0, at most one of the groups R₁, R₂ and R₃ is H.
 3. The method ofclaim 1, comprising a step of administering a compound having thefollowing formula (I-1):

wherein L′, R and R₂ are as defined in claim 1, or its pharmaceuticallyacceptable salts, racemates, diastereomers or enantiomers.
 4. The methodof claim 1, comprising a step of administering a compound having thefollowing formula (I-2):

wherein k, L″, R₁ and R₃ are as defined in claim 1, or itspharmaceutically acceptable salts, racemates, diastereomers orenantiomers.
 5. The method of claim 4, wherein, in formula (I-2), R¹ isan alkyl group.
 6. The method of claim 1, comprising a step ofadministering a compound having the following formula (I-2-1):

wherein Alk is a (C₁-C₁₂)alkyl group, and R is as defined in claim 1, orits pharmaceutically acceptable salts, racemates, diastereomers orenantiomers.
 7. The method of claim 1, comprising a step ofadministering a compound having the following formula (I-3):

wherein A₁, X₁, X₂, R, and R₁ are as defined in claim 1, or itspharmaceutically acceptable salts, racemates, diastereomers orenantiomers.
 8. The method of claim 1, comprising a step ofadministering a compound having the following formula (I-4):

wherein R is as defined in claim 1, and R₁ is an alkyl group comprisingfrom 1 to 12 carbon atoms, or its pharmaceutically acceptable salts,racemates, diastereomers or enantiomers.
 9. The method of claim 1,comprising a step of administering a compound having the followingformula (I-4-2):

wherein R is as defined in claim 1, or its pharmaceutically acceptablesalts, racemates, diastereomers or enantiomers.
 10. The method of claim1, wherein, in formula (I), R₁ is a (C₁-C₁₂)alkyl group.
 11. The methodof claim 1, wherein, in formula (I), R₁ is a (C₁-C₆)alkyl group.
 12. Themethod of claim 1, wherein, in formula (I), R₁ is an isopropyl group.13. The method of claim 1, wherein, in formula (I), R is a linear orbranched alkyl group, possibly interrupted by one or several doublebonds, comprising from 19 to 23 carbon atoms.
 14. The method of claim 1,wherein, in formula (I), R is a linear or branched alkyl group, possiblyinterrupted by one or several double bonds, comprising from 19 to 23carbon atoms, and wherein one or several hydrogen atoms are replaced bydeuterium atoms.
 15. The method of claim 1, wherein, in formula (I), Ris a linear or branched alkyl group, interrupted by at least one doublebond, comprising from 19 to 21 carbon atoms.
 16. The method of claim 1,wherein, in formula (I), R is the following radical:


17. The method of claim 1, wherein, in formula (I), R is the followingradical:


18. The method of claim 1, wherein the retinal pathology is Age-relatedMacular Degeneration (AMD) or Stargardt disease.